Rees pleaded not guilty to the complaint on the basis that any contact had been accidental. However, the independent Judicial Officer, Pat Barriscale (Ireland), reviewed all of the evidence and concluded Rees was guilty of foul play in contravention of Law 10.4(m) in that he had made contact with the eye/eye area of Mr Hartley.
The Judicial Officer found that the contact had been reckless but not intentional and also found that the offending was at the low end of the level of seriousness for an offence of this type, and having taken into account all aggravating and mitigating factors imposed a suspension of 12 weeks.
Rees is free to play again on 31st March 2011.
Speaking of the decision Rees said; "Having sought legal advice, with the support of the Blues and WRU, we have decided not to appeal against the decision.
"Naturally I am disappointed at the outcome of the hearing and to be suspended for 12 weeks. Missing out on the Six Nations and some crucial games for the Cardiff Blues is hugely disappointing and hard to accept.
"I felt it was worth looking at the possibility of an appeal as I am desperate to play for the Blues and Wales and naturally feel frustrated and disappointed at the outcome.
"However, I will now be concentrating on training hard in anticipation of the Magners League run in for the Blues in March and April and hopefully can still be part of the Rugby World Cup preparations with Wales."