Consumers from the UK and Mexico have joined the high-profile US class action lawsuit against Apple, alleging that the iPod Nano is defective in design because excessive scratching of the screen occurs during normal use.

The international plaintiffs filed their actions in the US District Court for the Northern District of California.

According to the complaint the world's largest manufacturer of portable music players knew of the iPod Nano's design flaws, but chose to ignore them in an effort to speed the product to market.

The plaintiffs further allege that the defect is a result of a much thinner layer of resin used in the Nano that does not provide adequate protection from scratching.

This follows a similar class action case filed on 19 October against Apple on behalf of iPod Nano users in the US.

Steve Berman, lead attorney on both cases, attributed the second suit to the large number of international requests to be included in the US class action.

"Apple's iPod Nano has sold in record numbers around the world, just as it did in the US," he explained. "It seems that wherever the Nano is sold, problems with the defective design soon follow."

Berman added that the global response reveals that this is not just a small problem or a rogue batch of Nano media players. "It is a defect in the overall design that should have been rectified prior to the release," he alleged.

Ben Jennings, one of the named plaintiffs in the UK, purchased an iPod Nano in September and claims to have been extremely careful with the screen.

Despite his efforts to protect the device, Jennings stated that within a week the screen was so marred with scratches that it became hard to read.

"If I had known the truth about the problem, I would never have purchased a Nano," he said.

Berman explained that residents outside the US are able to ask the court for help since Apple is headquartered in the US.

The latest suit seeks to represent and recover money lost for all those who live outside the US who purchased an iPod Nano.