MOSCOW, Jan. 23 - An espionage scandal redolent of the cold war unfolded Monday after Russia accused four British diplomats of spying and linked some of their activities to the financing of prominent private organizations, including the Eurasia Foundation and the Moscow Helsinki Group.

A grainy black-and-white video, broadcast on state television on Sunday night and shown repeatedly again on Monday, was said to show a British diplomat picking up a fake rock that was said to conceal a communications device used to download and transmit classified information through hand-held computers.

The rock, the size of a watermelon, and the device, said to be able to transmit and receive data at distances of more than 60 feet, were seized near Moscow, prompting a search across the city for similar devices, Sergei N. Ignatchenko, the chief spokesman for Russia's intelligence agency, the Federal Security Service, told Russian reporters, according to the Interfax news agency.

A second device was found, but "the British intelligence service managed to retrieve one of the gadgets," he said.