Liverpool defender Mamadou Sakho is being investigated by UEFA over a possible anti-doping rule violation, the Premier League club revealed on Saturday.

Sakho has not been suspended over the potential violation, but Liverpool have decided to leave out the France international while the probe continues and he was absent from the squad for Saturday's league fixture against Newcastle United at Anfield.

Reports in France claim Sakho tested positive for a fat burner after the Reds' 1-1 draw against Manchester United in the Europa League on March 17, but Liverpool have not confirmed those suggestions.

"Yesterday, Friday 22nd April 2016, a formal communication was received from UEFA stating that they are investigating a possible anti-doping rule violation by Mamadou Sakho," a statement on Liverpool's website read.

"The player will respond to UEFA on the matter. The player is currently not subject to any playing suspension.

"However, the club, in consultation with the player, has decided that while this process is followed the player will not be available for selection for matches."