Britain's security service MI5 literally pilloried V K Krishna Menon, veteran freedom fighter and India's first high commissioner to the UK, describing him as "dishonest, immoral and intriguer" and kept a tag on him for 30 years before and after independence.

According to the latest MI5 files released to the public, Menon's close links to Communists acted to block the sharing of British information with not only India, but also Pakistan, for fear that the two new states would compare their treatment by the British.

In all six files, covering the period 1929 and 1955, document the security service's interest in Krishna Menon, a close friend of Pandit Jawaharlal Nehru, India's first prime minister.

Menon's elevation to the post of Indian high commissioner to the UK increased the service's concerns about him.

The deputy director-general minuted in his file in May 1949: "Whatever his politics may be, and they appear to go fairly far to the Left, Menon is clearly dishonest, immoral, an opportunist and an intriguer. Whether or not Menon's retention as high commissioner is the lesser of two evils, the relations between him and Ms Tunnard are of considerable importance."

The matter of Communist influence at the high commission was raised at the Joint Intelligence Committee, in discussions that were not minuted.