Russian prosecutors launched a criminal investigation Thursday in parallel with the Scotland Yard-led probe into the killing of defector Alexander Litvinenko, who died of radioactive poisoning November 23, after a related murder attempt was allegedly made on one of his Russian contacts.
"The departure date has not yet been fixed, but most likely it will be in the next few days," the source said.
Experts from Scotland Yard arrived in Moscow Monday to interview people who met with Litvinenko around the time of his poisoning at the beginning of November.
The source said that Russian investigators would question businessman and former Federal Guard Service officer Andrei Lugovoi, a key witness in the Litvinenko case, who met the former Russian agent in London on the day of his poisoning.
"His testimony may have a major effect on the course of the investigation, and investigators may have more questions, which can only be answered in London," the source said.
Litvinenko, an outspoken critic of President Vladimir Putin's administration and a close associate of fugitive oligarch Boris Berezovsky, died in a London hospital after four days in a critical condition. His body was found to contain a lethal dose of radioactive polonium-210.
Litvinenko met with businessman Dmitry Kovtun on the same day he saw Lugovoi. Kovtun is now reported to have been hospitalized with similar symptoms.
