Baroness Chalker, Minister of State at the Foreign Office, told the House of Lords that the delegation visited Moscow to discuss the running of a security service in a democracy.
The disclosure followed a broadcast in English by Radio Moscow, and was raised in the Lords in a question by Lord Kennet, a Labour peer and former minister.
The radio station reported that US intelligence services were also talking to their Russian opposite numbers. Lord Kennet asked Lady Chalker what talks the British services were having with the Russians.
Lady Chalker replied that such arrangements depended on confidentiality and that ministers did not comment on them in any detail. However, in a break with tradition, she confirmed that the deputy director general of MI5, which covers security at home, visited Moscow in December 1991.
The deputy director-general was accompanied by a senior Home Office official. 'They discussed with the Russian security authorities the running of a security service within a democracy, a subject about which the Russians had expressed interest, and the prospects for co-operation on counter-terrorism.'
At the time of the visit, the Independent reported that Douglas Hurd, the Foreign Secretary, had protested to the former Soviet authorites about the continuing threat represented by an estimated 50 KGB and GRU (military intelligence) officers still operating in London.