Referee body PGMOL says it is taking the new allegations against Premier League official David Coote “very seriously”.
Coote is suspended from his position until an investigation into a video that emerged earlier this week in which the 42-year-old appeared to make derogatory comments about former Liverpool manager Jürgen Klopp.
On Wednesday, the Sun newspaper published images allegedly taken during this summer's European Championships, claiming they appeared to show Coote sniffing a white powder through a rolled-up US banknote.
Coote worked in his role as a match official at the European Championships.
A PGMOL spokesman said: “We are aware of the allegations and take them very seriously.”
“David Coote remains suspended pending a full investigation.
“David’s wellbeing remains of paramount importance to us and we are committed to continuing to provide him with the essential support he needs during this time. We are not in a position to provide further comment at this time.”