Two men have been arrested under the Official Secrets Act amid allegations that a parliamentary researcher spied for China.

The researcher is understood to have had links to several senior Tory MPs, including the security minister, Tom Tugendhat, and the foreign affairs committee chair, Alicia Kearns.

He was arrested along with another man by officers on 13 March, it was revealed by the Sunday Times.

Officers from the Metropolitan police’s counter-terrorism command, which oversees espionage-related offences, are investigating.

One of the men, in his 30s, was detained in Oxfordshire, while the other, in his 20s, was arrested in Edinburgh, Scotland Yard said. “Searches were also carried out at both the residential properties, as well as at a third address in east London,” it added in a statement.

Both men were held at a south London police station before being bailed until early October.

The Inter-Parliamentary Alliance on China pressure group said it was “appalled at reports of the infiltration of the UK parliament by someone allegedly acting on behalf of the People’s Republic of China”.

Tugendhat is said not to have had any contact with the researcher since before he became security minister in September last year.