Shocked by allegations published in The Australian on Friday, the NRL has instructed its integrity unit to speak to South Sydney officials.

The newspaper report alleged drug use and domestic violence by the former Rabbitohs captain, behaviour which was then alleged to have been covered up by the famous NRL club.

Burgess, an integral part of Souths NRL premiership success in 2014, denies the allegations.

His lawyer told The Australian "the allegations are false and constitute indefensible defamation against my client".

South Sydney are yet to comment.

However, the seriousness of the allegations has forced the NRL to start an investigation.

It comes just two days before Souths play a sudden-death finals match against Newcastle and hours before the NRL finals series kicks off in Sydney.

"These allegations are very serious and I've instructed the integrity unit to investigate the claims as a priority," NRL chief executive Andrew Abdo said.

"We will also seek the advice of police and other relevant authorities throughout this process.

"This is new information for the NRL and it is important we now gather the facts.

"The allegations have not yet been tested and due process will be followed as we undertake a thorough investigation.

"There is no place in our game for violence, harassment or abuse against women."

Abdo is due to face media later on Friday.

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