Penrith Panthers star Nathan Cleary is being investigated by the NRL over a possible breach of social-distancing rules.

The Panthers released a statement on Tuesday, confirming Penrith half-back Cleary is at the centre of an investigation.

Pictures emerged of Cleary with a group of women at his home on Anzac Day, in another blow to the NRL, which plans to restart the coronavirus-hit season on May 28.

"Penrith Panthers acknowledges the photos of Nathan Cleary being shared by the media in regards to social distancing regulations," the statement read.

"The club was first made aware of the photos on Tuesday morning and immediately forwarded them to the NRL.

"The matter is now in the hands of the NRL and the club will be making no further comment at this time."

It comes as South Sydney Rabbitohs star Latrell Mitchell and Melbourne Storm's Josh Addo-Carr face sanctions after breaking social-distancing rules.

The NRL duo were pictured breaking rules amid the COVID-19 crisis and New South Wales Police said on Monday they were investigating the matter.

Mitchell and Addo-Carr apologised later on Monday, though there have been calls for the pair to be suspended for the remainder of the season.

Australia's rugby league competition has been on hiatus since the NRL suspended the season through just two rounds on March 23.