THE OFFICE of Data Protection Commissioner Billy Hawkes is investigating a fault on Vodafone Ireland's mobile phone network which led to some 1,000 subscribers accessing voicemails left on other subscribers' phones.

It is believed that the investigation is likely to involve ComReg, regulator of the telecoms sector, which itself is examining the matter.

Vodafone declined to comment, stating only that it would co-operate with any investigation.

The company apologised to its subscribers on Monday.

Contrary to information supplied on Monday by Vodafone, the incident took place on Monday February 25th and on the following day.

An internal investigation had concluded on Monday March 3rd, said the company's spokeswoman.

A spokesman for Mr Hawkes's office said that Vodafone had alerted it to the problem.

"It is being investigated at the moment. We have been in contact with Vodafone. We're investigating the nature of data protection issues involved," he said.

The likely duration of the inquiry is not known at this time. Investigations by the office to ensure compliance with data protection law take the form of privacy audits.

"It is only in the event of serious breaches being discovered or failure of the data controller to implement recommendations that further sanctions would be considered", according to the commissioner's website.

The spokesman said that the office had not specifically investigated any similar incident in the past and added that it had not received any complaints from the public.

ComReg said that Vodafone informed it of the incident soon after it occurred.

"We asked them to give us a detailed report on what happened and what steps they are taking in relation to the matter," said a spokesman.