The International Committee of the Red Cross (ICRC) in Sri Lanka says it has contacted Tamil Tiger rebels over the case of a missing police inspector.
A letter sent to the leader of the political wing of the Tigers asks whether they know anything about T Jeyaratnam, who is a Tamil.
The ICRC said the letter had been sent in response to a complaint made to them by the wife of the missing inspector.
It says there are conflicting reports as to how he disappeared.
Correspondents say that one account is that he went out for dinner with a relative to a Colombo hotel on Wednesday (20 April), but did not report for duty the following day.
Police officials say that Inspector Jeyaratnam has been a major source of information about the activities of the Tamil Tigers and had spent 15 years in the police.
He is one of the few officers in the force regarded as an expert on terrorism.