LONDON — Olympic officials, acting on a tip-off from the World Anti-Doping Agency, are retesting some doping samples from the 2006 Winter Olympics in Turin to check for use of the blood-boosting drug CERA.

Four years after the games, WADA said Monday it received "new information" about possible misuse of CERA in Turin before the endurance-enhancing substance was put on the market.

WADA said it relayed the information to the International Olympic Committee, which decided to "conduct further analysis of a number of samples" collected in Turin.

"This analysis is ongoing," WADA president John Fahey said following the agency's executive committee and foundation board meetings in Montreal.

The IOC stores Olympic doping samples for eight years so they can be analyzed retroactively once new testing methods become available. Any drug cheats caught in the retests can be disqualified and stripped of their medals and results.

"An athlete who thinks he or she has got through a major event with some success through doping should continue to look over their shoulder because over the next years there is this capacity to reanalyze samples that have been stored," Fahey said in a conference call. "We're now seeing reanalysis of samples by the IOC from an event over four years ago."

The IOC had no immediate comment.

Last year, five athletes were caught when the IOC retested samples from the 2008 Beijing Olympics for CERA, an advanced version of EPO. Rashid Ramzi of Bahrain was stripped of his gold medal in the 1,500 meters.

Fahey said WADA received information about CERA use in Turin earlier this year and passed it on immediately to the IOC. He declined to say where the tip-off came from or elaborate on the evidence provided.

"WADA receives almost on a daily basis information from various sources," Fahey said. "All of it is taken seriously and examined properly. We simply pass that information on to the appropriate body. We will continue to keep our sources confidential, otherwise our intelligence is destroyed."

There was one positive test during the Turin Games, with Russian biathlete Olga Pyleva stripped of a silver medal after testing positive for a banned stimulant.

In addition, Italian police raided the lodgings of the Austrian cross-country and biathlon team outside Turin, seizing blood-doping equipment. No Austrian athletes tested positive at the time, but six were later banned by the IOC for involvement in the scandal.

In other developments at the WADA meetings, the executive committee approved the use of non-WADA accredited laboratories for conducting blood tests to support the agency's biological passport program.

WADA currently has 35 accredited labs, but says it needs forensic and clinical labs to help with blood analysis in parts of the world where there are no certified labs. That would eliminate the need for costly transport of samples between regions.

The biological passport program involves monitoring an athlete's blood profile over time to check for any changes that could indicate evidence of doping.

WADA also discussed the continuing review of the contentious "whereabouts" rule, which requires athletes to provide advance notice of their location so they can be found for out-of-competition testing.

WADA president John Fahey said the principle of the rule has overwhelming support but there is "still some misunderstanding from a number of anti-doping organizations as to the purpose of the whereabouts requirements."

Fahey said there was a need for "user friendly guidelines" to help sports federations and anti-doping bodies enforce the rule.

WADA also reviewed its cooperation with Interpol, saying more governments need to enact laws to crack down on the supply and trafficking of doping substances.