Harry Redknapp was questioned by police as part of the investigation into alleged corruption in English football, the Tottenham said. It is understood the Spurs boss was questioned by City of London Police officers and tax investigators.
The long-running investigation has focused on a number of transfer deals at Redknapp's former club Portsmouth and at Birmingham.
A spokesman for Spurs said: "It was a mere formality in respect of next stage information relating to a tax issue."
Both City of London Police and HM Revenue and Customs refused to comment.