SYDNEY (AP) — Five-time Olympic swimming champion Ian Thorpe says retesting of doping samples from previous games is a "good thing" and compared it with the solving of cold-case crimes.

The IOC says 31 athletes in six sports and from 12 countries could be banned from the Olympics in Rio de Janeiro after their doping samples from the 2008 Beijing Games came back positive in retests.

Thorpe says "for me it's not dissimilar to what happens with DNA testing, where they go back and there's people that may or may not have been convicted of a crime, and they can actually find them out now because of that procedure."