Reports from French Polynesia say about a dozen police have searched the premises of the opposition Tahoeraa Huiraatira Party as part of two inquiries, one of them into the alleged murder of a journalist in 1997.
This has been disclosed in a party statement which says today's search was led by a judge who refused to give details.
The Tahoeraa says the probe amounts to a public lynching of the party and its president, Gaston Flosse, who last year swore in the assembly that he never ordered or wished anybody's death.
A former spy of the GIP presidential force, Vetea Guilloux, had claimed weeks earlier that the missing journalist had been kidnapped and drowned off Tahiti.
This prompted the family of the journalist, Jean-Pascal Couraud, to lodge a formal murder complaint.
But last month in Papeete's court of appeal, the former spy was given a jail sentence for lying about his account of Couraud's disappearance while being acquitted of a conviction of criminal slander over the same case.
Guilloux has now appealed to a higher court in Paris.
The Tahoeraa premises had recently been searched in connection with a fraud probe over the purchase of an atoll three years ago when its leaders, including Mr Flosse, were in power.