LONDON, July 10: British police have asked mobile phone and Internet companies to store the content of voicemails, emails and SMS text messages that were in their systems on the day of the London bombings, a police source said on Sunday.

He said it was only the second time they had issued such a request. The first was in the wake of the Sept 11 attacks on the United States in 2001.

But police have no legal authority to force the companies to store the information, and some have said they cannot meet the request for technical reasons, the source said.

“The idea is to stop stuff that’s going to be important to the investigation disappearing,” he said.

“Over the next few weeks, as the Metropolitan Police identify suspects, they’ll want to investigate who they’ve been communicating with and so on. So the action is to make sure that data isn’t deleted routinely by the companies over that intervening period.”

Such information normally vanishes from the systems of telecom companies as soon as users have listened to their voicemail messages or download their emails, the source said.

This meant that companies which complied with the request would probably be able to retrieve the content of messages only from last Wednesday and Thursday.

A spokesman for BT Group confirmed the company had received the police request, issued on Thursday evening by the National Crime Squad. He declined to comment further, describing it as a security matter.

NEW EU RULES SOUGHT: Earlier, British Interior Secretary Charles Clarke said London would seek new European Union rules to make telecoms companies store records for much longer showing who their customers are calling and emailing.