"All mail and parcels from Japan need to go through our radiation test facilities in Taipei before they can be delivered to clients," said Tseng Chin-hsiung, the head of the company's mail business department.

The checks began Tuesday, he told AFP, adding that so far no radiation had been detected in the mail from Japan.

The company handles more than 50,000 parcels and 20 tonnes of letters from Japan each month, Tseng said.

A 9.0-magnitude earthquake and ensuing tsunami struck Japan on March 11, severely damaging a nuclear power plant, with 9,737 people now confirmed dead and 16,501 listed as missing by national police.