Newton has made 15 international appearances for Great Britain
Wakefield Trinity Wildcats have cancelled the contract of former Great Britain hooker Terry Newton following his two-year ban from all rugby.
Newton last week opted not to contest the charge brought by the UK Anti-Doping Agency for taking a self-administered human growth hormone.
That triggered an automatic two-year ban for the close-season signing from Bradford which runs to November 2011.
The 31-year-old is the first athlete in the world to test positive for HGH.
"There has been a feeling that you can take growth hormone with impunity but this shows this is no longer the case," said UKAD chief executive Andy Parkinson.
"We have heard from others that growth hormone is being abused by athletes but until now investigations have been of the non-analytical type."
Newton's two-year ban, confirmed by UKAD on Monday, will be from all codes of rugby - and is dated from the day he failed the drugs test in November.
A UKAD press release confirmed: "Mr Newton will be ineligible to play, coach or otherwise participate in any World Anti-Doping Code-compliant sport until 23 November 2011."
Wakefield coach John Kear told the BBC's Super League Show that the club had no choice but to cancel Newton's contract.
"It is a big blow for the club, but more for the player, because Terry has been a great servant to the game," he said.
I don't think this will effect the morale or motivation of my team
Wakefield coach John Kear
"As a club, we have an education process on these kinds of things and we had to take the stand we did with Terry."
Newton's ban takes the shine off the Wildcats' great start to the season, which has seen them win their opening three matches to stand second behind leaders Wigan.
But Kear insisted: "I don't think this will effect the morale or motivation of my team.
"They just have to remain positive and professional.
"We are not feeling sorry for ourselves. We feel sorry for Terry and his family."
The club statement read: "Following a UKAD investigation and Terry Newton's admission that he breached the RFL's doping control regulations, his contract with the Wakefield Trinity Wildcats has been cancelled with immediate effect.
"Wakefield Trinity Wildcats are fully supportive of the RFL's principles of a drug-free sport.
"The club works hard to inform its players about the dangers of drugs and consequences of taking drugs, or breaching the anti-doping regulations."