He was expected to face a two-year ban after cocaine was found in his system following Castleford Tigers’ game against his former club Leeds Rhinos last September.
But Hardaker - who admitted the offence and was sacked by Castleford in February ahead of today’s announcement - saw his legal team argue that as a result of a ‘number of exceptional circumstances’ he ‘bore no significant fault in committing an Anti-Doping Rule Violation (ADVR).’
Following a one day hearing in front of the National Anti-Doping Panel, the 26-year-old was charged by UK Anti-Doping.
Hardaker, the 2015 Man of Steel, was represented by Leeds-based Chadwick Lawrence Solicitors who, in a statement, said: “We believe the correct verdict has been returned and we would like to thank the Tribunal for their professionalism.
“This was a truly exceptional case, where the drug use was never linked to performance enhancement.
“In this regard Zak would never take any substance to achieve an unfair advantage and we are pleased that the decision of the Tribunal has recognised this fact.
“He was commended by the Tribunal for his impressive comprehensive evidence and the fact that he made no attempt to downplay his conduct and was utterly frank with them.
“The last two years have been an extremely difficult period for Zak who, away from the public eye, has bravely battled a number of personal traumas.
“Zak has asked for privacy at this time but thanked his family and close friends for helping him through this difficult period.”
Pontefract-born Hardaker, who won the treble with Leeds in 2015, had enjoyed a brilliant debut season at Tigers when news of his failed drugs test broke just two days before their Grand Final appearance against Rhinos in October.
Castleford had won the League Leaders’ Shield - by a record margin of 10 points - for the first time in their history and also reached a maiden Grand Final.
However, with their plans in disarray after Hardaker’s shock omission, they lost 24-6 at Old Trafford.
Castleford had initially taken him on a season-long loan from Leeds but paid a £150,000 transfer fee to their rivals in June and handed him a four-and-a-half year contract.
Hardaker - who is reportedly ready to sign with Wigan Warriors for 2019 - was suspended on September 8 2017, which means he will be eligible to return to play the sport on November 7 this year.