According to The Daily Mail, United are keeping tabs on the Algeria international, who has been in superb form so far this season.
"I don't have any contact with Manchester United about Mahrez,” Kamel Bengougam told ESPN FC. "He is only focused on this season with Leicester City.”
Mahrez joined Leicester from French club Le Havre in January 2014 and has been one of the best players for them.
The 24-year-old has been playing brilliantly this campaign and has been one of the best players in the Premier League.
The former Quimper man has scored seven goals and created 23 chances in 10 league appearances so far this season.
Mahrez has a pass accuracy of 74% and a shot accuracy of 61%, and has won 11 headers, 36 dribbles and nine tackles.
Leicester are third in the Premier League table at the moment with 22 points from 11 matches, just three points behind leaders Manchester City.