Germany’s former spy chief, August Hanning, has been arrested on suspicion of passing state secrets to a foreign intelligence service.

Hanning, 80, headed up the Federal Intelligence Service, known by its German acronym BND, from 1998 to 2005.

A federal prosecutor’s statement said it strongly suspected him of “treasonous espionage, obtaining state secrets, attempted treason” through contact with foreign intelligence services since 2010, while working as a private consultant. He is accused of obtaining around 2,000 sensitive documents from a former bureau chief who has also been arrested.

But he isn’t the only high-ranking intelligence officer to have been discovered to have worked for foreign governments over the years. Here are some of the highlights. 1940s to 1960s – Kim Philby and the ‘Cambridge Five’Kim Philby was a British intelligence officer who secretly spent decades working for the Soviet Union during World War II and the early Cold War years.

He was recruited by Soviet Intelligence while studying at Cambridge University in the 1930s. He was the most prominent member of the “Cambridge Five” – a spy ring that gave away British secrets to the Soviet Union.

During the war, he joined MI6, where he rose to head its counter-Soviet division, and was later posted to Washington, DC. This gave him access to sensitive information through his close links to the CIA and FBI.

His tip-offs to his Soviet handlers are believed to have scuppered many Western operations and revealed the identities of agents. This included information operations to overthrow Albania’s communist leader Enver Hoxha as part of Western efforts to stop the spread of communism.

Philby came under suspicion in 1951 and was forced out of MI6 when Guy Burgess and Donald Maclean, two other members of the Cambridge Five, defected to the Soviet Union. Philby was suspected of having warned them that British intelligence officers were close to uncovering their identities as double agents for the Soviet Union, before being formally cleared of the allegations in 1955.

Then, in 1963, aware that the net was closing in on him because of his own involvement with Soviet intelligence, he fled to Russia, where he lived with his wife since 1971, Rufina Pukhova, until his death in 1988. Overall, he provided state secrets, the identities of agents, minutes from cabinet meetings, atomic research, diplomatic and military intelligence, and information about counter-intelligence operations to the Soviet Union for nearly 20 years. Philby is regarded as the most damaging spy in British history.

According to the UK’s National Archives, one of the agents he unmasked to the Soviet Union was Constantin Volkov, a Soviet intelligence officer posted to Turkiye who wanted to defect to the UK in 1945. Volkov and his wife were seized and executed in Moscow as a result. The information he provided to the Soviet Union about a joint CIA-MI6 operation in communist Albania in the late 1940s and early 1950s resulted in the execution of hundreds of anti-communist agents.

Kim Philby, British intelligence agent, laughs with reporters during a 1955 news conference after being formally cleared of tipping off fellow double agents Guy Burgess and Donald Maclean [File: Getty Images] 1970s and 1980s – Oleg Gordievsky Oleg Gordievsky was a KGB colonel who spied for British intelligence for more than a decade.

He was the son of an officer in the NKVD, which was the Soviet secret police and the direct predecessor to the KGB.

But he was recruited by MI6 in the early 1970s after becoming disillusioned by the Soviet crushing of mass protests during the Prague Spring in Czechoslovakia in 1968 and the building of the Berlin Wall.

While working for the KGB, he was stationed in Copenhagen and later in London, where he became KGB station chief in 1985.

The intelligence he provided to the British is thought to have revealed the KGB’s deep concerns that NATO’s 1983 Able Archer exercise might be cover for a real nuclear strike. This was invaluable for helping the West understand Soviet fears and to de-escalate.

Gordievsky came under suspicion and was recalled to Moscow in 1985. He was drugged and interrogated but had not yet been charged when MI6 ran a daring operation to rescue him and smuggle him out of Russia in the boot of a car across the Finnish border. Russia sentenced Gordievsky to death in absentia. He lived in the UK under protection until his death in 2025.

Oleg Gordievsky, the KGB Colonel-turned-British spy, is seen here wearing a disguise at the Marlborough Hotel in London, on October 16, 1990 1980s and 1990s – Robert Hanssen Robert Hanssen was a high-ranking agent at the US Federal Bureau of Investigation (FBI) who spied for the Soviet Union and later for Russian intelligence services between 1979 and 2001.

Hanssen initially studied dentistry at Northwestern University before switching courses and receiving a degree in accounting and information systems. He worked as a police officer in Chicago before joining the FBI in 1976.

He approached Soviet military intelligence in 1979, eventually working with the KGB and its successor, the SVR. He operated using the alias “Ramon Garcia”.

Hanssen never met his handlers in person, instead using “dead drops” when he would leave classified documents in prearranged outdoor locations, including parks, wooded areas, under bridges and on street corners in the Washington, DC area, in exchange for cash or diamonds.

He handed over thousands of pages of classified material, including details about US nuclear war plans and the identities of Russian officials working for the US. At least two of those sources, including Dmitri Polyakov and Valery Marynov were executed.

The arrest in 1994 of Aldrich Ames, another US spy caught working for Russian intelligence, eventually led to his arrest in February 2001.

He pleaded guilty to avoid the death penalty and died in prison in 2023. An undated FBI-issued photograph of Robert Hanssen, a former FBI agent deemed a traitor by the government and considered one of the most damaging spies in US history 2000s – Alexander Yuk Ching Ma Alexander Yuk Ching Ma is a former CIA officer who was caught spying for China.

He worked for the CIA from 1982 to 1989 and became a US citizen, living in Honolulu.

In March 2001, officers of China’s Shanghai State Security Bureau asked him to arrange a meeting with a now-deceased former CIA officer who served from 1967 to 1983. The two met in a Hong Kong hotel room for three days. In exchange for $50,000, they provided classified information to China.

The FBI became aware of his ties to Chinese intelligence and hired him as a contract linguist in its Honolulu office so that his activities could be monitored.

He was arrested in a sting after admitting to an undercover FBI employee that he had facilitated the provision of classified information to Chinese intelligence. Ma pleaded guilty in May 2024 and is currently serving a 10-year prison sentence.