SYDNEY, AUSTRALIA - OCTOBER 03: Raiders Coach, Ricky Stuart speaks during the NRL Grand Final Press Conference at the Westin Hotel on October 03, 2019 in Sydney, Australia. (Photo by Brendon Thorne/Getty Images)

NRL agent Isaac Moses has revealed the true reason why John Bateman will leave the Canberra Raiders at the end of the season, hitting back at fiery comments made by coach Ricky Stuart.

On Tuesday, Stuart blasted "certain managers" who "manipulate communications and negotiations" in a press conference just hours after Bateman informed the club of his decision not to see out his contract for 2021.

Bateman's decision has angered the Raiders, who paid a $358,000 transfer fee to secure his services from his former club Wigan.

Moses has defended in role in the decision, claiming it was salary-cap issues and not greed that lead to Bateman leaving the club.

"My job is to look after the best interests of my clients, which I have always done, without fear or favour," Moses said in a statement published in The Sydney Morning Herald.

"On 24 February I met with [Canberra CEO] Don Furner, Ricky Stuart and John in Canberra to discuss John's future at the Raiders.

"At that meeting Don advised the club were in salary cap trouble. 2021 was very tight and they were in the process of trying to re-sign other players in addition to John. 2022 was worse, they weren't going to be able to afford him at all.

"After that meeting, on 11 March I received an email from Don giving permission for John to talk to other clubs as the Raiders weren't in the position to accommodate him long term.

"To Don's credit, he always said he didn't want to stand in John's way should he wish to look at other opportunities for the betterment of his young family.

"He made it clear the club isn't in the habit of letting good players go, but was honest about the difficulties of managing their roster of the back of a grand final, with unanticipated Origin bonuses to also factor in."

Moses also revealed it was Canberra and not Stuart who agreed to a clause in Bateman's contract to revisit his salary at the end of every season.