Transport Minister Michalis Liapis asked British Airways yesterday to provide information on two planes on which traces of a radioactive substance were found and which had passed through Athens.

“This is a serious case. We have asked British Airways to give us information and to view the radioactive traces so that we can see how to handle the situation,” said the minister.

British Airways warned yesterday up to 33,000 customers that it had found traces on board two planes of the radioactive poison linked to the death of former Russian spy Alexander Litvinenko. The planes flew to various destinations, including Athens and Larnaca. It was not known how many of those passengers were Greek or Cypriot.

“British Airways understands from the advice that it has been given that the risk to public health is low,” the airline said.

Passengers who have traveled with the airline recently can visit its website or call 0044.191.211.3690 to determine whether they might be affected by the radioactive substance and need to seek medical advice.