British investigators have found minute traces of polonium 210, the radioactive isotope that killed former Russian spy Alexander Litvinenko, at a London soccer stadium, a public health spokeswoman said on Tuesday.
The traces were found at the stadium of English Premier League club Arsenal.
"Minute quantities (of polonium) were found at barely detectable levels at localised areas," said Health Protection Agency spokeswoman Katherine Lewis. "There is no risk to public health."
British police are in Moscow investigating Litvinenko's death in a case that has strained ties between Britain and Russia since the exiled former spy on his death bed accused Russian President Vladimir Putin of ordering his assassination.
Litvinenko died in a London hospital on Nov. 23 from a lethal dose of polonium 210 after falling ill on November 1.
One of the men British police want to question in Russia is Andrei Lugovoy who travelled to London on October 31 with his wife and three children to watch CSKA Moscow play Arsenal in a Champions League game on November 1.
He met Litvinenko at a London hotel earlier the same day.
