Greater Manchester Police have been called in to investigate death threats made to Ben Flower following the incident which marred last weekend's Super League Grand Final.
The Wigan Warriors prop was sent off just two minutes into his side's 14-6 defeat against St Helens at Old Trafford for twice striking opponent Lance Hohaia.
Flower was subsequently handed a six-month ban by the Rugby Football League, while police are now probing remarks made to the Wales international on Twitter.
"We've been made aware of abusive social media activity about the Rugby League Grand Final. Please be reassured that we are looking into this," Greater Manchester Police revealed.
The full extent of the messages has not been disclosed, although Sky Sports News claims that death threats were made to Flower in the days following the game.
Hohaia was also banned for one game for his part in the altercation.
