The radioactive element believed to have killed ex-Russian agent Alexander Litvinenko has been detected in another central London restaurant.
Mr Litvinenko died in London on 23 November 2006
Polonium-210 was found at the Pescatori Restaurant in Mayfair and staff are being tested, health officials said.
The police had asked the Health Protection Agency to monitor the establishment as it was "linked to the Litvinenko police investigation".
A total of 12 people in London have now tested positive for radioactivity.
In a statement, the agency said there was no reason for public health concern over the latest discovery.
"Remediation measures have been carried out successfully at the restaurant which is now open for business," the statement said.
Restaurant manager Luigi Lavarini told BBC News he was happy with the way health officials had dealt with the contamination.
"We're being reassured very much by the good work of the Health Protection Agency.
"They have been very reassuring that none of us should have any problems because of this.
"The only precaution they are asking us to take is to do this urine test which we will be undergoing in the next few hours."
Mr Litvinenko died in London on 23 November and his body was found to contain a massive dose of the radioactive isotope polonium-210.
Since then, traces of the element have been discovered in several restaurants and hotels.