RugbyL: Two South Sydney players rushed to hospital

Australian police are investigating after two rugby league players were rushed to hospital Tuesday, with reports that an adverse reaction to painkillers may be the cause.

South Sydney Rabbitohs Dylan Walker and Aaron Gray were reportedly found in a serious condition at Gray's apartment in eastern Sydney when paramedics were called, but both have now stabilised.

The club confirmed that Walker, a 20-year-old who last year won the premiership with South Sydney and played for the Kangaroos, and rising star Gray, 21, were in hospital.

"Both players had post season surgery last week, following the end of the club's season," it said in a statement.

"The club is keeping abreast of the situation and will not be making any further comment at this stage."

New South Wales police, who did not name the men, confirmed they were investigating "a report that two men were taken to hospital after being treated by ambulance personnel who had been called to a home in Rosebery about 3:30am".

South Sydney were knocked out of the NRL finals earlier this month, and both Walker and Gray had undergone surgery in preparation for pre-season training later this year.

Each had been prescribed the painkiller Oxycodone, Nine News reporter Danny Weidler tweeted, adding there was no evidence that alcohol had been involved.

"What has been confirmed by Dylan Walker's agent through his sister... Dylan Walker had some kind of reaction to the drugs Oxycodone and (painkiller) Tramadol," Weidler told The Today Show.

"He's had an operation recently. They are drugs used in relation to pain. We are not sure exactly yet of what Aaron Gray has reacted to, why he was there."

National Rugby League chief Dave Smith said officials were aware of the incident and the welfare of the players was the priority.

"Our priority is two men are in hospital and we keep our fingers crossed they turn out good. Anything we need to investigate we will," he told reporters.