Google started selling video content on its video site in January last year, offering programs such as Survivor, CSI and Star Trek for about $1.99 (£1).

Google co-founder Larry Page launched the service at the Consumer Electronics Show, in Las Vegas, but the success of YouTube has made Google Video increasingly irrelevant.

Jupiter analyst David Card said Google's decision to stop people from watching content they had already bought from the service was a mistake.

"No wonder consumers are still a bit cautious about digital content," he wrote on his blog.

He added: "We've seen a physical format-device combo go out of manufacture before: wax cylinders, 8-tracks. But can you think of any consumer-purchased medium that actually becomes unusable while there are players that still work?"

Google said users would be offered a Google Checkout credit of $5 (£2.50), which would expire within 60 days.