The British authorities are also interested in a fifth plane, in their inquiry into the death of Litvinenko, according to Reid.
“There is one other Russian plane that we know, that we think we would be interested in. There may be other airplanes… But those are the five we know of,” Reid said.
The Health Protection Agency is expected to clear one of the three British Airways aircraft identified as having possible radioactive contamination. The aeroplanes operate the London-Moscow route.
“The police found very low traces of a radioactive substance on board two of the three aircraft”
Litvinenko, a former Russian agent who became a leading critic of Vladimir Putin, the Russian president, died of radiation poisoning in a London hospital last week.