THE funeral of former Russian spy Alexander Litvinenko will be held in London today, two weeks after his death.

Mr Litvinenko's body will be buried in an air-tight coffin, in a private ceremony, after he was poisoned with the deadly radioactive isotope polonium-210.

His father, Walter Litvinenko, said the 43-year-old, who was born an Orthodox Christian but had close links to Islamist rebels in Chechnya, would be buried according to Muslim tradition.

He said his son had requested it as he lay dying in University College Hospital after apparently converting to Islam in his final days.

Friends and family said prayers for him at the Central London mosque in Regent's Park this morning but the body could not be taken there because of the contamination.

The burial will take place at an undisclosed location at 2pm today.

'Murdered'

The funeral comes as Scotland Yard confirmed that they were treating Mr Litvinenko's death as murder.

"Detectives in this case are keeping an open mind and methodically following the evidence," a police statement said. "It is important to stress that we have reached no conclusions as to the means employed, the motive or the identity of those who might be responsible for Mr Litvinenko's death."

Small traces of a radioactive substance were found at the British Embassy in Moscow yesterday but officials stressed that it presented no health risk.

Businessman and ex-KGB agent Andrei Lugovoy - one of three Russians who met Litvinenko at the Millennium Hotel in London on the afternoon he was poisoned - had been to the embassy to give a statement following his death.

Minimal traces were also found at Arsenal's Emirate's Stadium, in north London, where Mr Lugovoy watched Arsenal play CSKA Moscow in a Champions League game on November 1.

Police have been questioning Mr Lugovoy in the presence of Russian officials in hospital, where he was undergoing tests for contamination.

Italian academic and nuclear expert Mario Scaramella, who also met Mr Litvinenko on the day he was taken ill and later tested positive for polonium-210 himself, has been discharged from hospital.

After five days of observation and tests, Mr Scaramella, who had a 20th of the dose that killed his friend, said: "All my tests are negative and I am not showing signs of poisoning."

Sushi bar cleared

The London sushi restaurant Itsu, where Mr Scaramella had lunch with the former KGB agent, has now been given the all-clear after being closed for two weeks for decontamination.

The Health Protection Agency said that radiation at the site was at "barely detectable levels" and that there was no danger to the public.

All 31 employees have been given a clean bill of health and the restaurant hopes to reopen early next year.

The Piccadilly sushi bar is one of about a dozen places where traces of polonium-210 were found.

Staff at Barnet Hospital are expected to hear shortly if they have been contaminated by the radiation which killed Mr Litvinenko.

Fears that staff at both hospitals may have been contaminated prompted the HPA to test 71 nurses and doctors across both centres.

A spokeswoman for the hospital said of the tests on Barnet staff: "The HPA have found nothing of concern in the urine samples tested so far. The agency will be contacting those people who gave samples to inform them of their results."

Police believed Mr Litvinenko may have been poisoned at the restaurant and were investigating the possibility that he was followed there.

However, Mr Scaramella said he thought the theory unlikely: "I don't believe it happened there, simply because there were no other people, not any strange situation," he told the Cable News Network.

Scotland Yard said today that detectives were continuing their investigations in Russia and the UK.

Russia warned earlier this week that any suspects from the country would not be extradited to the UK.