A post-mortem examination is to be carried out on the body of the former Russian spy Alexander Litvinenko, who died from radiation poisoning.
Mr Litvinenko died last week in a London hospital
Those present will wear protective clothing to avoid contamination by traces of the polonium-210 isotope.
The probe into his death has seen two planes tested for radiation and a third is flying back from Moscow for checks.
It has emerged Culture Secretary Tessa Jowell and Olympics chief Lord Coe travelled on one of the aircraft.
The pair took a British Airways flight to Barcelona in November on board one of the two planes that have already been tested for traces of radiation.
A spokesman for Ms Jowell said the minister had contacted the NHS for health advice but was at no medical risk and was "very unperturbed".
This came as Russia reiterated assurances it would co-operate fully with the inquiry into Mr Litvinenko's death.
Russian Foreign Minister Sergei Lavrov said: "The ball is now with Britain, everything depends on British investigators".
The post-mortem on Mr Litvinenko's body will be carried out at the Royal London Hospital, in east London.
Mr Litvinenko, an ex-KGB officer and critic of Russian President Vladimir Putin, died last week of radiation poisoning attributed to the highly toxic isotope polonium-210.
The investigation into the spy's death has unearthed traces of radiation at 12 locations.
That includes the two British Airways planes, which tested positive after being used to fly between London and Moscow, as well as other European routes.
British Airways is contacting 33,000 passengers from 221 flights, but the airline and the government have stressed any risk to public health low. It is referring concerned passengers to NHS Direct.
An NHS Direct spokeswoman said only passengers who feel unwell should call.
A total of 217 people have been seen by a specialist assessment clinic.
Contact with carrier's sweat or urine could lead to exposure
But polonium-210 must be ingested to cause damage
Radiation has very short range and cannot pass through skin
Washing eliminates traces
Investigators may be able to trace the origin of the polonium-210.
Ian Hutcheon, an expert in nuclear forensics, said: "If you have samples of the material, you can gather information about where they were or were not produced by analysing trace constituents."
On Friday the British Embassy in Moscow said there was no information to suspect any link between Mr Litvinenko's death and the illness of former prime minister of Russia Yegor Gaidar.
Mr Gaidar fell ill last week on a visit to Ireland and his daughter Maria told the BBC doctors believe he was poisoned. Police are investigating.
Meanwhile, the FBI said it had been asked to join the British investigation into Mr Litvinenko's death and that its experts in weapons of mass destruction would assist with some of the scientific analysis.
The inquest into the death of Mr Litvinenko was opened and adjourned at a London court on Thursday.
Friends of Mr Litvinenko say Russian intelligence agents plotted to kill the former spy.
Polonium-210 was discovered in his body, with more traces found at venues he visited in London on 1 November.
British Airways has set up a special helpline for customers in the UK on 0845 6040171 or +44 191 211 3690 for international calls.
Passengers who travelled on those flights and want further advice are advised to telephone NHS Direct on 0845 4647.