In an Interview with 60 Minutes Hamilton said that he, along with Armstrong, used performance enhancing drug to better compete in the Tour de France.
"The IOC has taken note of Hamilton's confession and will of course study any potential games-related implications. We will contact UCI and USADA for further information," the IOC said in a statement.
In a public letter to friends and fans Hamilton writes:
"During my cycling career, I knowingly broke the rules. I used performance-enhancing drugs. I lied about it, over and over. Worst of all, I hurt people I care about. And while there are reasons for what I did -- reasons I hope you'll understand better after watching -- it doesn't excuse the fact that I did it all, and there's no way on earth to undo it."
"If there is any need or possibility to take action we will do it," said Bach, who heads most of the IOC's doping investigations.
According to the AP:
"The IOC can retroactively strip Olympic medals if proof of doping emerges later or an athlete admits to cheating. The IOC took away Marion Jones' five medals from the 2000 Sydney Games after she admitted using performance-enhancing drugs.
The IOC had provisionally investigated Hamilton for doping after he won the time trial gold at the 2004 Athens Olympics.
An initial test at the Athens Games suggested the American had received an endurance-boosting blood transfusion. But the case was dropped after his backup sample was mistakenly frozen, leaving too few red blood cells to analyze.
If the IOC disqualifies Hamilton, his former U.S. Postal Service teammate Viatcheslav Ekimov of Russia stands to be upgraded from silver."