Watford are being investigated by the Football League for allegedly supplying false financial information.
Watford won Premier League promotion that season, and could have points deducted or be fined if they are found to be at fault.
Watford told the Telegraph they are carrying out an internal investigation.
An EFL spokesman confirmed it had started an investigation into “serious allegations” and had contacted the club after receiving information from the newspaper.
He said Watford had been asked to “provide a full and detailed response to the allegations”.
The Telegraph claims the “fabricated” document shows that the holding company which owns Watford – Hornets Investment Ltd – had enough money to be issued a bank guarantee of up to £7m and therefore allow Italian Pozzo to take control of the club.
The newspaper says there is no indication that Pozzo himself knew that the letter had been obtained or submitted on his behalf.