Warriors assistant coach Richard Agar has received a three-match ban and $10,000 fine for allegedly grabbing a journalist by the throat at the NRL's showpiece event in Las Vegas.

The NRL issued Agar with a breach notice on Monday following the incident that is alleged to have happened on game day at Allegiant Stadium on March 2.

Half of his fine will be suspended pending any further offences, with Agar unavailable to serve on Andrew Webster's coaching staff for upcoming clashes against the Sydney Roosters, Wests Tigers and Melbourne.

He has been barred from travelling with the Warriors for the second two of those three matches, both in Australia.

Agar, who previously coached Super League sides Hull FC, Wakefield Trinity and Leeds Rhinos, will also be required to undertake "appropriate education and training".

The Englishman has five business days to respond to the breach notice

According to the reporter in question, Agar confronted him backstage at Allegiant Stadium, where the Warriors lost 30-8 to Canberra in the first game of the season.

Agar and the reporter are believed to have known each other from the coach's time working in England.

The English-based journalist had been on site to cover matches between Super League sides Wigan and Warrington, and the England women's team and Australia.

Agar previously worked with Webster on Samoa's coaching staff, and joined the NRL club for the Warriors head coach's first season at the helm in 2023.