GENEVA, March 20 (Xinhua) -- Russia on Tuesday said it had not been conducting any researches whatsoever into the Novichok nerve agent allegedly being used in the recent poisoning of a former Russian spy and his daughter on March 4 in Britain, and it had nothing to admit because it was "not guilty".

"With the fall of the Soviet Union, the laboratories for the production of nerve agents of this category remained in a whole series of other countries," a Russia diplomat said, adding that Russia "did not exclude the possibility that the United Kingdom itself had the potential to produce the said nerve agent".

The Geneva-based Conference on Disarmament on Tuesday heard an update from the United Kingdom on steps taken to investigate the alleged use of Novichok nerve agent in Salisbury on March 4.

According to the British representative speaking at the Conference, investigators from the Organization for the Prohibition of Chemical Weapons had arrived in the United Kingdom on March 19.

The samples they would collect would be sent for testing to a "highly reputable international laboratory" selected by the Organization for the Prohibition of Chemical Weapons, the UK representative said, and the results of the testing of the samples were expected in two weeks.

During Tuesday's meeting, Russia insisted on the UK's obligation to provide concrete evidence and all the information required, saying it would only engage in a "genuine dialogue" on the basis of certified samples, witness statements and other investigative materials.

"Russia failed to understand the legal basis for the independent analysis of the United Kingdom's own investigation and insisted on the United Kingdom's obligation to provide concrete evidence and all the information required," a Russian representative said during the meeting.

British authorities have claimed that the nerve agent Novichok was used in the poisoning of Sergei Skripal and his daughter Julia on March 4 in the southern English city of Salisbury.

Sergei Skripal, 66, is a former Russian spy before he became a double agent for Britain.

London has demanded Moscow explain why the nerve agent that traces back to Russia should end up in Britain. Moscow has denied any involvement.