WASHINGTON: A group backing US President Barack Obama released a biting Olympics-themed ad Wednesday attacking Republican rival Mitt Romney as he heads to London for the Games.

In the video, Priorities USA Action used archive images from the opening ceremony of the 2002 Salt Lake City Winter Olympics that Romney ran and is credited with saving from bankruptcy.

The ad shows a radiant Romney as he waved to the cheering crowd as delegations entered the stadium. In the assumed voice of a sportscaster, the accompanying commentary takes aim at Romney's record at companies he headed, as well as his alleged foreign investments.

"There's Mitt Romney, who ran the Salt Lake City Games, waving to China, home to a billion people. Thousands owe their jobs to Mitt Romney's companies," the voiceover says sarcastically.

It then makes reference to India, saying it "also gained jobs thanks to Romney, an outsourcing pioneer."

"We know the Swiss have a special place in Mitt Romney's wallet ... He kept millions in Swiss banks," the voice-over says as the camera closes in on the Swiss delegation. "Those Swiss sure know how to keep a secret!"

The ad continues with reference to Bermuda and the Cayman Islands, considered offshore tax havens.

"There's Bermuda, home to a secretive corporation set up by Romney. No one knows why and Romney won't tell. And the Cayman Islands where Romney keeps millions to avoid US taxes."

The ad concludes with: "You've got to say this about Mitt Romney: he sure knows how to go for the gold -- for himself."

Release of the video comes as Romney -- who hopes to end Obama's tenure in the White House in November 6 elections -- is expected to attend Friday's opening ceremony of the Olympics in London. He will then continue on to Israel and Poland. AGENCIES