NEW YORK (AP) _ Former champion Pernell Whitaker tested positive for a banned substance before winning a fight two weeks ago, his co-manager confirmed today.

``We were told by the commission that the test came back positive,'' said Shelly Finkel. ``We've asked our lawyers to get all the papers, and we will respond.''

Finkel said Whitaker, in discussing the results of the pre-fight urine test, told him ``it's a joke.''

The test was given prior to Whitaker's 12-round victory over Russian Andre Pestriaev on Oct. 17 at the Foxwoods Casino in Ledyard, Conn. The decision put Whitaker into a WBA welterweight title fight against Ike Quartey of Ghana in the spring.

Whitaker was sent a letter this week informing him that he had been placed under administrative suspension by the Pequot Tribal Commission which supervises boxing at Foxwoods, according to the New York Daily News.

``Pernell said he didn't get anything yet,'' said Dino Duva, Whitaker promoter.

Whitaker has 30 days in which to appeal the findings.

The usual penalty for a first-time offender would be a six-month suspension, according to an unidentified commission member quoted by The News.

Whitaker, who has been regarded as boxing's best ``pound for pound'' fighter, has no record of using banned substances.