Former athlete Lord Sebastian Coe has insisted that drug cheats need to be hit with harder penalties in light of recent events involving Asafa Powell and Tyson Gay.

Gay tested positive in an out-of-competition test in May, while Powell used a banned stimulant during the Jamaican Championships last month.

Coe believes that the current two-year ban for those found guilty of drug enhancement in the sport is not an adequate punishment.

"I've really been fighting this one for as long as I've been a competing a senior athlete," Coe told talkSPORT. "I think a mistake was made a couple of years ago and that was to reduce the ban for a positive test from four years to two years. That gave the chancers an opportunity.

"My personal view is that we've got to get that back to a four-year ban. That would almost certainly take out an Olympic games.

"At the moment, with a two-year ban, by the time they've appealed and done all the things they can do it's really only an 18-month ban. I don't think it's proportionate to the damage that's been done."

The Anniversary Games takes place in London this week.