POLICE remain tight-lipped about a drug-trafficking investigation embroiling AFL great Mark Thompson.

Thompson, 54, was questioned by police on Tuesday after presenting himself at the police station. He was not charged following the interview, pending further inquiries.

It followed a police raid on Friday of a property Thompson owns at Port Melbourne.

"All we've done so far is confirm that we did execute warrants at that premises and that he came and spoke to our police late yesterday afternoon," Chief Commissioner Graham Ashton told reporters on Wednesday.

"The investigations on that case, I'm told, are continuing.

"We need the investigation still to run its course. We are not providing further commentary on top of what's happened to date."

Three people have been charged with drug trafficking following Friday's raid at Port Melbourne and another search at Geelong.

The trio were remanded in custody and are due to face court at Geelong at a later date.

Police said the arrests were part of an ongoing investigation into drug trafficking.

It's unclear how Thompson is allegedly connected.

Thompson, 54, led the Cats to premierships as coach in 2007 and 2009 and played in Essendon's 1984, 1985 and 1993 flags.

He was fined $30,000 for his role in the Bombers' supplements scandal which saw 34 past and present players suspended for the 2016 season.