The International Olympic Committee is disappointed by the decision to allow 400 meters champion LaShawn Merritt to run at the London 2012 Games -- and will seek an amendment to their overturned rules, president Jacques Rogge said on Friday.

The IOC had ruled that every athlete sanctioned for more than six months for a doping offence, would not be eligible to participate in the next Olympic Games.

However, their rule was overturned earlier this month after an appeal from Merritt at the Court of Arbitration for Sport.

In 2010 Merritt received a 21-month ban after having tested positive for a banned substance. The suspension ended in July this year and he competed at the world championships the following month.

Speaking at a news conference in Auckland where Rogge was attending the rugby World Cup, the Belgian IOC president said: We are of course a bit disappointed, because we believe the rule was protecting the clean athletes and that is absolutely our philosophy, because we have a zero tolerance approach in the fight against doping.

However, the IOC has been a party in creation of CAS, together with International Federations, therefore we will accept the decision and not appeal.

What we will do, however, is find new wording in a similar rule in the next amendment of the WADA anti-doping code.

The anti-doping code will be amended between now (November 2011) and November 2013 when a new code will be voted and implemented.

We are seeking to have a similar possibility with another WADA rule.