Two people allegedly working as spies for British intelligence have been arrested in Moscow, a Russian MP has told a television programme.
Last week, Russian TV showed what it said was the spy rock
"They are not silent they are talking," Nikolai Kovalyov, the former head of the security service said.
There is no official confirmation of the claims, which are due to be broadcast on Sunday evening.
It is not clear if the men are linked to last week's spying claims allegedly involving British embassy workers.
The UK Foreign Office said Britain was asking the Russian foreign ministry for information.
"We have not been notified but it is not clear whether this report is about British staff," a spokesman said after Mr Kovalyov's comments in a trailer to the programme on Russia's NTV television in which he referred to two "British spies" being arrested.
On Wednesday, Russian President Vladimir Putin said officials were still considering how to respond to the alleged UK spy scandal.
Last week's TV programme said four officials from the UK embassy and one Russian citizen, allegedly recruited by the British secret service, downloaded classified data from a transmitter in a fake rock planted in the street onto palm-top computers.
The programme also said a UK diplomat made regular payments to Russian non-governmental organisations.
The UK Foreign Office expressed surprise at the allegations and denied any improper behaviour.