"They arrived yesterday to hold earlier planned meetings with their British colleagues to discuss ways of cooperating," the diplomat said.
He also said Alexander Zvyagintsev, a deputy Russian prosecutor general, heads the group, and added that the prosecutors will be working in Britain for several days.
Zvyagintsev said nothing about whether the arrival of the Prosecutor General's representatives is connected with the investigation into the death of former Russian Federal Security Service (FSB) officer Alexander Litvinenko.
Litvinenko, 44, who defected in 2000, died in London November 23. Doctors said a lethal dose of radioactive polonium 210 was found in his body. Before his death, Litvinenko accused the Kremlin of orchestrating his poisoning in a deathbed note, a charge that President Vladimir Putin strongly denied.
Detectives from Scotland Yard and the Russian Prosecutor General's Office have been investigating the case in London and Moscow.
On March 12, Zvyagintsev told a respected Russian daily, Izvestia, that Russian investigators would like to question more than 100 people in the U.K. as part of the Litvinenko case investigation.
"We have made a list of over 100 people whom we want to interview in Britain, including Russians living there. Moreover, we are seeking permission to examine a number of facilities and conduct other investigative procedures," Zvyagintsev told Izvestia.
He said work had already begun, adding that the list included tycoon Boris Berezovsky, who lives in London as a political emigre.
Earlier, Berezovsky, who is wanted in Russia on charges of fraud and attempts to overthrow the Russian government, said he would meet with Russian investigators in London only if his security was guaranteed.
Zvyagintsev said March 12 that British law enforcement agencies had given no official information on the involvement in the poisoning of agent-turned-businessman Andrei Lugovoi, a key witness in the Litvinenko case.
Lugovoi and another witness, former security service agent Dmitry Kovtun, met with Litvinenko in a London hotel shortly before he was hospitalized with symptoms of poisoning, and have themselves undergone radiation checks.
Both have denied any involvement in Litvinenko's death.
