Tottenham say they are looking into claims that midfielder Yves Bissouma was filmed inhaling nitrous oxide.
The Sun published footage which it alleged showed the 29-year-old Mali international inhaling the substance, also known as laughing gas or NOS.
“We are looking into the events and it will be dealt with as an internal matter,” a club spokesperson told BBC Sport.
Bissouma, a £30m signing from Brighton in 2022, was banned for one game by Spurs after being pictured inhaling nitrous oxide in 2023.
He apologised, saying he displayed a “severe lack of judgement”.
Possession of nitrous oxide for recreational use has been a criminal offence in the UK since 2023 and can result in a two-year prison sentence.
Bissouma, whose contract expires at the end of the season, has not played since Thomas Frank was appointed manager in June.
Bissouma was left out of the squad for the UEFA Super Cup game against Paris St-Germain in August because of persistent lateness, and has struggled with ankle and knee injuries this season.