The post-mortem examination of poisoned spy Alexander Litvinenko was ‘one of the most dangerous ever undertaken in the Western World’, a pathologist revealed yesterday.

Dr Nathaniel Cary said the former KGB agent was carried to a secure room in two body bags because of the radiation coming from it.

Taking no chances with safety during the three-hour autopsy, pathologists each wore two biochemical suits, two pairs of gloves and specialised hoods fitted with battery-powered breathing packs to avoid being contaminated by polonium-210.

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Poisoned: Alexander Litvinenko's body was highly radioactive after his death, an inquiry has heard

Hearing: Marina Litvinenko, left, with her solicitor Elena Tsirlina outside the Royal Courts of Justice

An expert was also on hand to wipe off any blood spatters and to monitor the team for any effects of radiation poisoning, the public inquiry into Mr Litvinenko’s death was told.

Home Office pathologist Dr Cary said paramedics were also on standby because ‘it would have been a disaster if anyone had fainted or had an acute medical problem’.

Describing how the London Ambulance Service had put a ‘casualty evacuation’ plan in place, he added: ‘I think it was felt that this was such a dangerous post-mortem to carry out that we really only wanted to do it once if at all possible.

‘It has been described as one of the most dangerous post-mortem examinations ever undertaken in the Western world, and I think that’s probably right.’

The former spy and critic of Vladimir Putin died from acute radiation poisoning in 2006 after two Russian hitmen are said to have laced his tea with polonium-210 at the Millennium Hotel in Mayfair.

Evidence: Pathologist Nathaniel Cary, left, and detective inspector Craig Mascall, right, were among those who addressed the inquiry yesterday

Widow: Marina Litvinenko is pictured arriving for the second day of the inquiry

Dr Cary had earlier told the inquiry how the body had presented a ‘considerable hazard’ on the intensive unit it was on at University College Hospital, London.

After sealing the room and taking a tissue sample from Mr Litvinenko’s right thigh, the body was wrapped in two body bags before being taken to a secure room for examination, he said.

The Royal Courts of Justice were told how Mr Litvinenko had ingested a ‘large quantity’ of polonium-210 and the amount his body absorbed was ‘in far excess of known survivability limits’.

Dr Cary added: In terms of weight it’s a very tiny amount, but in terms of polonium-210 it is a large quantity.’ Mr Litvinenko, 43, is the first recorded person to have been killed by the highly radioactive chemical – a billionth of a gram of which is fatal and one gram could be enough to kill 100million people.

The inquiry heard that polonium-210 emits alpha radiation rather than gamma radiation.

That means it is only dangerous if it gets inside the body, where it continuously bombards cells as it is distributed around. The court was also told how hospital doctors were initially baffled over the cause of Mr Litvinenko’s deteriorating condition.

MURDER SUSPECT WAS CHARGED IN 2007 - BUT 'COULDN'T CARE LESS' The alleged murderer of Alexander Litvinenko, a former KGB officer who is now a Russian MP, declared last night that he 'couldn't care less' about the inquiry. Andrei Lugovoi was charged with killing Mr Litvinenko nearly eight years ago, but has never stood trial as he cannot be extradited from his native country. The Russian dissident was apparently poisoned with polonium while meeting Lugovoi and businessman Dmitri Kovtun at the Millennium Hotel in Mayfair. Lugovoi had previously visited London twice within the previous month - and during one of his trips, Mr Litvinenko was the target of a botched poisoning attempt. After the ex-spy's death, attention focussed on Lugovoi as the principal suspect, and in May 2007 the Crown Prosecution Service charged him with murder. Russian authorities refused to extradite him to the UK, saying it would be against their constitution, but offered to put him on trial in his home country. Lugovoi's deviance of the British government has made his a cause celebre in Russia, and he was elected as an MP in late 2007. In 2012, he passed a televised lie-detector test which supposedly cleared him of Mr Litvinenko's murder - but critics claim that the device is nothing more than pseudo-science. Today Ben Emmerson QC, who represents the dead spy's widow Marina, read out part of an interview that Lugovoi gave to Echo of Moscow last night, in which he claimed that the inquiry was politically motivated. 'When the situation in Ukraine kicked off and the UK's geographical interest had likely begun to change, they had decided to dust off the moth balls and commence proceedings,' he said. He added that he 'couldn't care less about what's happening' in the inquiry, and claimed that he had not been asked to give evidence. Lugovoi concluded: 'This is an old story you are rehashing, an old story now.' Advertisement

Two days before his death medics decided ‘on a hunch’ to carry out specific tests which showed up polonium-210 poisoning.

Another pathologist, Dr Benjamin Swift, said diagnosis was difficult because it was the ‘only case in the world’. ‘It would not have been forefront in the thought process of anyone and would not have been identified in routine toxicology,’ he said.

Ben Emerson QC, representing the Litvinenko family, suggested it would be a good poison for anyone who wanted the cause of death to go undetected.

He said: ‘The rarity of polonium-210 agent makes it so hard to detect. He was dying slowly over 23 days. It was not until the last day of his life polonium was identified. If this poison was administered as a means of murdering it would be very difficult for the cause of death to be identified.

‘Whoever made that decision [to use polonium-210] must have had access to a very highly specialised degree of scientific knowledge.’

The hearing continues.

Family: Alexander Litvinenko pictured with his wife Marina (left) and son Anatoly in London in 2000

Suspects: Dmitry Kovtun, left, and Andrei Lugovoi, right, have been accused of killing Mr Litvinenko

Litvinenko's teapot was 'covered with radiation traces', leading nuclear scientist tells inquiry

The teapot from which Alexander Litvinenko drank shortly before falling ill had 'off the scale' levels of radiation traces, the inquiry was heard.

One of the country's top nuclear scientists - known only as 'Scientist A1' because of her secret work on the UK's nuclear deterrent - gave evidence to the hearing this afternoon.

She was shown a 3D model of a teapot taken from the Millennium Hotel where Mr Litvinenko was allegedly poisoned in November 2006.

The levels of radiation on the teapot were 'off the scale', she said, adding: 'The probe wouldn't be able to measure any higher.

Meeting: Mr Litvinenko was apparently poisoned at the Millennium Hotel in Mayfair, pictured

'There was a considerable amount of activity in the spout. It is more than probable this is the source of primary contamination. There was a form of polonium within the teapot.'

Polonium-210 was also found in a hotel room occupied by Andrei Lugovoi, she told the inquiry.

Scientist A1 said that the radioactive isotope is not present in nature, and to make a small amout it is necessary to take 'tonnes of material' and mix it in a nuclear reactor.

She added that it would be impossible to tell where the substance was made simply by examining its structure.

The deadly substance could easily be dissolved in liquid and would potentially be invisible to the naked eye, the hearing was told.

'In solution it often forms a colloid, a very fine distribution within the water matrix,' Scientist A1 said.

'It could be possible to detect it with human eye, you may not be able to. If it's completely soluble you won't be able to see it.'