From the NY Daily News’ TJ Quinn :

Yankee officials have asked the New York Police Department to find out who has been calling media outlets claiming that Jason Giambi tested positive for steroids.

Sources said the man, who identified himself as team president Randy Levine’s assistant, called local and national outlets over the past week with information that Giambi had failed Major League Baseball’s drug test.

The caller, authoritative and knowledgable, said MLB would announce the failed test on Friday.

Levine wouldn’t return a call for comment, but a team source said they weren’t sure whether it was someone with an ax to grind or a prankster. Levine does not have a male assistant, and according to the team source and an MLB source, Giambi has not tested positive. He has been tested at least once this season.

“If he had, everybody would know,” the source said. “He’s been clean.”

(authorities are looking for the man in the above photograph. Allegedy, he’s also been calling Brian Cashman in a girly voice saying he wants to have the Yankee GM’s retarded babies.)