An Italian security consultant who tested positive for traces of the same radioactive substance that was found in the body of a poisoned ex-KGB spy is not showing any signs of illness, doctors said Saturday.

Mario Scaramella met with former Russian agent and Kremlin critic Alexander Litvinenko at a central London sushi bar on Nov. 1. Later that day Litvinenko reported feeling unwell, and the 43-year-old died three weeks later — his body withered, his hair fallen out and his organs ravaged.

Scaramella, 36, was "well" and preliminary tests had shown "no evidence of radiation toxicity," said a spokesman for University College Hospital, where Litvinenko died and Scaramella is having tests.

Tests on Friday confirmed that Scaramella had been exposed to polonium-210, the rare substance found in Litvinenko's body before he died in London on Nov. 23. But doctors said Scaramella had been exposed to a much lower level of the radioactive material.

Scaramella's Naples-based lawyer, Sergio Rastrelli, told Italy's Sky TG24 TV that the Italian wasn't in isolation and was meeting with doctors and police.

"He was exposed to the same source as Litvinenko, but at a lower level," Rastrelli said. Scaramella was showing "no external symptoms."

"It's possible he ingested or inhaled the same substance at the same place as the Russian", Rastrelli said, "although fortunately in exponentially lower doses."

Scaramella has said that he didn't eat anything at the sushi restaurant when he was there with Litvinenko because it was after lunchtime.

Separately Saturday, the Greek Health Ministry that four Greeks are being tested for possible contamination with polonium-210.

The four recently stayed at a London hotel visited by Litvinenko, Deputy Health Minister Thanasis Yiannopoulos said. The four, who have not been identified, are undergoing blood and urine tests at the state-run Dimokritos nuclear research center, the ministry said. Results are expected early next week.

Also on Saturday, British Airways announced that all three of its jetliners that had been grounded by investigators looking into Litvinenko's death had been cleared to resume service. Small traces of radioactive substances had been found on the planes.

The Health Protection Agency, or HPA — which deals with public health issues in Britain -- said though very low levels of polonium 210 were found on two of the planes, there was no risk to passengers.

Another airline, easyJet, said Scaramella had flown with them to London from Naples on Oct. 31 and returned on Nov. 3, two days after his meeting with 43-year-old Litvinenko. The HPA said there was no risk to the public from those flights.

A hotel and London's Emirates Stadium, where some of Litvinenko's contacts attended a soccer game, were also searched but no public health hazard was found, the agency said. A total of 24 people have now been referred for tests for possible radiation exposure.

Litvinenko's wife Marina, 44, was also confirmed as having shown traces of polonium, but she was showing no ill effects and did not need hospital treatment, the ex-spy's friend Alex Goldfarb said Saturday.

Goldfarb said Marina cared for her husband at their north London home for two days before he was hospitalized on Nov. 3.

The Italian Health Ministry has ruled out any danger to public health in Italy — where Scaramella returned following his visit to London.

Italian Health Ministry official Donato Greco traveled to London Saturday to follow the case first hand, health officials in Rome said.

Scaramella, who had been working for the Italian Parliament's Mitrokhin Commission investigating KGB activity in Italy, told Litvinenko Nov. 1 about an e-mail he received from a source naming the purported killers of Russian investigative journalist Anna Politkovskaya, who was gunned down on Oct. 7 at her Moscow apartment building. The e-mail reportedly said that he and Litvinenko — a friend of the reporter — were also on the hit list.

In Ireland, meanwhile, officials said tests on former Russian Prime Minister Yegor Gaidar were negative for radiation poisoning.

Gaidar became violently ill during a conference in Dublin last week — an incident his aides have described as another poisoning. He is now being treated at a hospital in Moscow, where his condition has been described as improving.

Three pathologists on Friday completed Litvinenko's autopsy at the Royal London Hospital, coroner Dr. Andrew Reid said. Police said results may not be available for several days.

Litvinenko's funeral is expected to take place in London next week. Due to the levels of radiation in his body the coffin will be sealed.