I have five times lethal poison dose, claims spy contact

Mario Scaramella, a security adviser and nuclear expert, is being treated at University College Hospital. Doctors said he is "well" and displaying no signs of radiation poisoning. But he is not yet in the clear.

Read more:

• Detectives fly to Moscow in poisoning probe

• Reid briefs EU meeting over Litvinenko death

• Was blackmail plot behind the spy poisoning?

In a statement issued today he said: "The urine examinations found traces of polonium significantly lower than that which was used to kill Mr Litvinenko, but they were still considered to be potentially lethal and therefore capable of killing me."

Speaking late last night from his hospital bed in a telephone interview on Italian TV, he added: "I have five times the lethal amount of polonium in my body so my humour is not at its best."

As the mystery deepens, Mr Litvinenko's death will be discussed today at a meeting of EU ministers in Brussels. Home Secretary John Reid said he would be exchanging information with colleagues at the European Council.

Meanwhile, Scotland Yard is closing in on the leading suspects in the plot.

Detectives are flying to Moscow this week to question five men, including one who made several trips to London in the fortnight before the former spy fell ill.

Ministers have been briefed on his identity and he is considered a "key" suspect. Nine anti-terror officers from the Met will fly to Russia, where they will be shadowed by local police.

Andrei Lugovoy, a former KGB agent turned millionaire entrepreneur, is believed to be among those police want to meet. He made three trips to London from 16 October and met Mr Litvinenko four times in the days before he was poisoned.

Intriguingly, it is claimed that traces of polonium-210 have been found at a hotel where Mr Lugovoy stayed before meeting Mr Litvinenko.

Security sources say that Mr Lugovoy is reported to retain close contacts within Russia's Federal Security Service, the FSB. Alex Goldfarb, a close friend of the victim, revealed that on his death-bed Mr Litvinenko voiced his suspicions about him.

Mr Lugovoy denies involvement in the death, and said that he would welcome the chance to clear his name.

The latest theory to emerge in the mystery is that Mr Litvinenko was planning to blackmail several wealthy Russians about their private lives and business dealings.

Meanwhile, the Health Protection Agency said just over 3,000 people had called the NHS Direct line in the wake of the radiation scare in the UK, with 179 being followed up for further investigation.

Twenty-seven people were referred as a precaution to a specialist outpatient clinic for radiological exposure assessment.

A total of 70 urine samples, mainly from medical staff and ambulance workers, have been tested and found negative.