The iPod mini contains a Hitachi 4GB hard drive

The iPod mini launched in the US last month and has been a huge success, with reports of shops being out of stock and a thriving export trade on eBay.

Apple says it will only have enough stock to satisfy world-wide demand for the device in July.

The music player has a 4GB hard drive which can store up to 1,000 songs and costs $249 (�137).

Apple's iPod is the most popular digital music player in the world and more than two million have been sold world-wide.

Revolutionising

Greg Joswiak, Apple's VP of Hardware Product Marketing, told BBC News Online that demand for the iPod mini had been incredible.

"It's been really popular with people exercising, with women, who are an important demographic, and with teens."

The problem lies with the miniature hard disc drive at the heart of the iPod mini: Apple is buying all the stock of drives as fast as Hitachi can manufacture them.

"We're actually consuming just about all the 4GB, one-inch drives they make. As they make more, we'll get more," said Mr Joswiak.

The device is credited with revolutionising the way people listen to their music collection.

The iPod and iPod mini work with Apple's iTunes software and can play songs that have been bought online as well as MP3 files.

Unfortunately, like the iPod mini, the iTunes music store is only available in the US.

Mr Joswiak denied that Apple was neglecting Europe or other countries.

He said the company had had to take the "difficult decision" to delay the launch so that there would a strong supply of stock in July rather than releasing the iPod mini in April and creating immediate supply problems.

Mr Joswiak was unable to say how much the iPod mini would cost when launched outside the US.