Mr Litvinenko's house had been sealed off
The family of poisoned Russian agent Alexander Litvinenko have been given back the keys to their home after it was declared free of radiation.
Mr Litvinenko, 43, died in November 2006 after being poisoned with Polonium-210.
His home in Muswell Hill, north London, was inadvertently contaminated by him and has remained vacant for two years.
Haringey Council said scientists have confirmed the property has been adequately decontaminated.
It is not sure whether his wife Marina and their son Anatole will move back to the house. They had lived there for three years.
Haringey councillor Nilgun Canver said: "The family home of the late Alexander Litvinenko, who died from Polonium-210 poisoning in November 2006, has now been deemed safe for habitation and the keys have been returned to Mrs Litvinenko.
Mr Litvinenko, 43, died in London after being poisoned
"Scientists from the Health Protection Agency have monitored the radiation levels at the property and have now advised that the property has been adequately decontaminated and the restrictions can be withdrawn.
"Much of the contamination found in earlier surveys has naturally decayed in the intervening time, so only minimal further remediation work has been necessary."
Mr Litvinenko, who was a fierce critic of former Russian President Vladimir Putin, drank Polonium-210 which was put into his drink at a West End hotel.
UK investigators suspect former KGB agent Andrei Lugovoi of the murder, but he has always denied any involvement.
In May 2007, the Crown Prosecution Service formally submitted an extradition request to Moscow for Mr Lugovoi to stand trial in the UK.
That request remains current, but Russia has refused to cooperate saying it would be against its constitution to do so.