The International Weightlifting Federation says it has been notified of 20 positive tests, including medal winners, among the retested doping samples from the 2008 and 2012 Olympics

In a statement sent to The Associated Press, the IWF said Monday it was informed by the International Olympic Committee of 10 cases from the 2008 Beijing Games and 10 from the 2012 London Games.

It said the Beijing tests were "presumed" positives that still require "B" sample analyses. The 10 from London were described as confirmed positives.

The IWF says the cases include medal winners. It did not give any names or nationalities.

The 20 cases account for a large part of the total of 55 positives which the IOC has reported so far, including 32 from Beijing and 23 from London.