The welcome page of MI5

According to Wikipedia and their official website, the Security Service, commonly known as MI5 (Military Intelligence, Section 5), is the United Kingdom's domestic counter-intelligence and security agency and is part of its intelligence machinery alongside the Secret Intelligence Service (MI6), Government Communications Headquarters (GCHQ), and Defence Intelligence (DI). MI5 is directed by the Joint Intelligence Committee (JIC), and the service is bound by the Security Service Act 1989. The service is directed to protect British parliamentary democracy and economic interests and to counter terrorism and espionage within the United Kingdom. Within the civil service community, the service is colloquially known as Box, or Box 500, after its official wartime address of PO Box 500; its current address is PO Box 3255, London SW1P 1AE.

The Security Service began as the Home Section of the Secret Service Bureau, founded in 1909. At the start of the First World War, it was responsible for the arrest of enemy spies, or suspected enemy spies. Throughout the First World War, Germany continually attempted to infiltrate Britain, but MI5 was able to identify most, if not all, of the agents dispatched. During the Second World War, it developed the Double-Cross System. This involved attempting to "turn" captured agents wherever possible, and use them to mislead enemy intelligence agencies.

After the war, the service was instrumental in breaking up a large Soviet spy ring at the start of the 1970s. It then allegedly became involved in monitoring trade unions and left-wing politicians. It also assumed responsibility for the investigation of all Irish republican activity within Britain during The Troubles. Its role was then expanded to countering other forms of terrorism, particularly in more recent years the more widespread threat of Islamic extremism. In 1996, legislation formalised the extension of the Security Service's statutory remit to include supporting the law enforcement agencies in their work against serious crime. They work with lots of other organisations to help keep the country safe. This includes the UK’s other intelligence agencies, SIS and GCHQ as well as the police and government departments. They also work with the private sector and academic institutions.

LEGALITY

Operations of the service are required to be proportionate, and compliant with British legislation, including the Regulation of Investigatory Powers Act 2000, the Investigatory Powers Act 2016, the Data Protection Act 2018, and various other items of legislation. Information held by the service is exempt from disclosure under section 23 of the Freedom of Information Act 2000. The Security Service Act of 1989 establishes several legal key mechanisms aimed at ensuring the accountability and control of the Service. Certain provisions from this act were later integrated into the Intelligence Services Act of 1994 with European Commission on Human Rights later having endorsed these mechanisms in multiple applications under the European Convention on Human Rights. Additionally, all employees of the service are bound by the Official Secrets Act.

The Security Service "is authorised to investigate any person or movement that might threaten the ... security" of the United Kingdom.

OVERSIGHT

The Service is subject to oversight and accountability through various means. These oversight mechanisms have evolved over time to meet changing governmental requirements, with the Service now being held accountable through a variety of oversight arrangements.

It is directly answerable to the Home Secretary, and is also overseen by:

1. The Intelligence and Security Committee of Parliament, which is directly appointed by the Prime Minister.
2. The Investigatory Powers Commissioner.
3. The Investigatory Powers Tribunal.

SERIOUS CRIME

In 1996, legislation formalised the extension of the Security Service's statutory remit to include supporting the law enforcement agencies in their work against serious crime. Tasking was reactive, acting at the request of law enforcement bodies such as the National Criminal Intelligence Service (NCIS), for whom MI5 officers performed electronic surveillance and eavesdropping duties during Operation Trinity. This role has subsequently been passed to the Serious Organised Crime Agency (SOCA) and then the National Crime Agency (NCA).

SURVEILLANCE

In 2001, after the September 11 attacks in the US, MI5 started collecting bulk telephone communications data under a little understood general power of the Telecommunications Act 1984 (instead of the Regulation of Investigatory Powers Act 2000 which would have brought independent oversight and regulation). This was kept secret until announced by the Home Secretary in 2015. This power was replaced by the Investigatory Powers Act 2016 which introduced new surveillance powers overseen by the Investigatory Powers Commission (IPC) it introduces.

In July 2006, parliamentarian Norman Baker accused the British Government of "hoarding information about people who pose no danger to this country", after it emerged that MI5 holds secret files on 272,000 individuals, equivalent to one in 160 adults. It had previously been revealed that a 'traffic light' system operates:

- Green: active; about 10% of files
- Amber: enquiries prohibited, further information may be added; about 46% of files
- Red: enquiries prohibited, substantial information may not be added; about 44% of files.

CRIMINAL ACTIVITY OF MI5 OFFICERS

In March 2018, the government acknowledged that MI5 officers are allowed to authorise agents to commit criminal activity in the UK. Maya Foa, the director of Reprieve, said: "After a seven-month legal battle, the prime minister has finally been forced to publish her secret order, but we are a long way from having transparency. The public and parliament are still being denied the guidance that says when British spies can commit criminal offences, and how far they can go. Authorised criminality is the most intrusive power a state can wield. Theresa May must publish this guidance without delay".

In November 2019, four human rights organisations claimed that the UK government has a policy dating from the 1990s to allow MI5 officers to authorise agents or informers to participate in crime, and to immunise them against prosecution for criminal actions. The organisations said the policy allowed MI5 officers to authorise agents and informers to participate in criminal activities that protected national security or the economic well-being of the UK. The organisations took the UK government to the Investigatory Powers Tribunal, seeking to have it declare the policy illegal, and to issue an injunction against further 'unlawful conduct'. In December 2019, the tribunal dismissed the request of the human rights organisations in a 3-to-2 decision. The potential criminal activities include murder, kidnap, and torture, according to a Bloomberg report.

ALLEGATIONS OF COLLUSION IN TORTURE

In October 2020, Rangzieb Ahmed brought a civil claim against MI5, alleging that Pakistan's Inter-Services Intelligence agency had arrested him in 2006, and that MI5 had colluded in torture by submitting questions which were put to him under torture in Pakistan. This claim was rejected by the High Court on 16 December 2020.

DOMESTIC ABUSE SCANDAL

In May 2022, the BBC reported on an unnamed MI5 agent, 'X', domestically abusing his partner, despite the British government's attempts to block this. BBC journalists subsequently discovered that MI5 lied to courts, suggesting that the organisation was unaware of X's behaviour, including his far-right extremist views. An ongoing High Court case began in June 2025, with MI5 accepting that X's status should no longer be protected, after previously neither confirming nor denying his role as an agent.

DIRECTOR GENERALS

1909–1940: Sir Vernon Kell (born 1873 – d. 1942)
1940–1941: Oswald Allen Harker (born 1886 – d. 1968)
1941–1946: Sir David Petrie (born 1879 – d. 1961)
1946–1953: Sir Percy Sillitoe (born 1888 – d. 1962)
1953–1956: Dick White (born 1906 – d. 1993)
1956–1965: Roger Hollis (born 1905 – d. 1973)
1965–1972: Martin Furnival Jones (born 1912 – d. 1997)
1972–1979: Michael Hanley (born 1918 – d. 2001)
1979–1981: Howard Smith (born 1919 – d. 1996)
1981–1985: John Jones (born 1923 – d. 1998)
1985–1988: Antony Duff (born 1920 – d. 2000)
1988–1992: Patrick Walker (born 1932 – d. 2021)
1992–1996: Stella Rimington (born 1935 – d. 2025)
1996–2002: Stephen Lander (born 1947)
2002–2007: Eliza Manningham-Buller (born 1948)
2007–2013: Jonathan Evans (born 1958)
2013–2020: Andrew Parker (born 1962)
2020–present: Ken McCallum (born 1974)

Corruption lurks in every corridor of local and national buildings.

MEDIA OFFICE

Journalists with enquiries about 

REFERENCE

https://www.mi5.gov.uk/

https://www.gchq.gov.uk/

https://www.ncsc.gov.uk/
https://www.sis.gov.uk/

https://www.mi5.gov.uk/

https://www.gchq.gov.uk/

https://www.ncsc.gov.uk/
https://www.sis.gov.uk/