Motorola is investigating a faulty batch of its popular Razr mobile phone, which has already led two mobile operators in the US to stop selling the device.
Motorola is also investigating whether any of the faulty phones have reached the European market.
Both Cingular and T-Mobile in the US have stopped selling the Razr, after a bug cut off callers or shut down the phone when the flip of the slim-line phone was opened.
Motorola is hopeful of re-releasing the phone to these two US networks later this week. It is not known how many users have been affected by the problem.
Motorola has sold over 12 million Razr handsets since the first Razr models were launched in 2004.
A faulty component is believed to be the cause of the problem, and the faulty batch is said to have been shipped between this January and February.
The bug only affects those handsets operating on standard GSM networks, and not more advanced 2.5G and 3G networks.