Liverpool have said they are aware of footage of striker Raheem Sterling apparently taking nitrous oxide.
Pictures published on The S*n‘s website appear to show the England international passing out unconscious after taking the substance, described as a legal high.
A club spokesperson said: “We are aware of the story and intend to speak to the player. Any subsequent action will be taken internally.”
Liverpool manager Brendan Rodgers was expected to address the issue further in his post-match press conference.
The matter comes at a time when considerable controversy surrounds 20-year-old Sterling following the apparent breakdown of contract talks with the club.
Sterling risked the wrath of supporters by admitting he had rejected a £100,000-per-week deal in a recent interview that was not sanctioned by the club.
Another newspaper also published pictures of him allegedly smoking a shisha pipe over the weekend.