The US men's 4x100 relay track team has been stripped of its silver medal from the 2012 London Olympics following an American sprinter's doping conviction.

The US Olympic Committee (USOC) was notified of the disqualification in a letter from the International Olympic Committee (IOC).

The decision came in the wake of Tyson Gay's conviction last year after he tested positive for steroids at the US championships in 2013.

"We will begin efforts to have the medals returned, and support all measures to protect clean athletes," USOC spokesman Patrick Sandusky said in a statement on Wednesday.

Mr Sandusky acknowledged the decision was expected by the American Olympic committee.

International rules permit an entire team can be disqualified and stripped of medals if one of its members tests positive for performance-enhancing drugs.

The Americans set a national record in the final at the London Games with a time of 37.04 seconds. The team finished second to the Jamaican team anchored by Usain Bolt.

The IOC could reallocate the silver medals to Trinidad and Tobago, which finished third. The bronze would then go to the French team, which came in fourth.

Gay returned his medal last year after accepting a one-year doping suspension.

His ban included the loss of results going back to July 2012, when he first used a product containing a banned substance.

The other US team members who also must now return their medals are Trell Kimmons, Justin Gatlin, Ryan Bailey, Jeffery Demps and Darvis Patton.

Kimmons, Gatlin and Bailey ran in the final with Gay.

Gatlin, who is in Qatar for the opening Diamond League meet of the season on Friday, told the AP news agency he was not aware of the decision and had no comment.

Gatlin, who won the 100-meter gold medal at the 2004 Games in Athens, served a four-year doping ban from 2006.

The IOC has previously stripped American relay teams of medals retroactively for doping, including three teams from the 2000 Sydney Olympics.
(Sky News)