Hackers continue to hog the headlines this morning, with fresh doubts being cast on the origin of over a million Apple UDID codes that were allegedly stolen from an FBI agent’s laptop before being posted online by AntiSec.

Late last night, the FBI issued a strenuous denial that one of its laptops was compromised, and moreover, insisted that it had no interest in either collecting or storing this kind of data from Apple device users.

The rebuttal was issued following claims by the hacktivist group AntiSec that it had swiped the data from an FBI agent named Christopher Stangl, who is based at the Bureau’s Regional Cyber Action Team in New York. The hackers said that their goal in stealing the data and posting it online was to expose the fact that the agency is secretly collecting information from Apple users, which they allege can be used to log the GPS location and track the movements of anyone using an Apple device.

Unsurprisingly, the FBI has angrily denied that it’s involved in this, releasing the following statement:

“At this time there is no evidence indicating that an FBI laptop was compromised or that the FBI either sought or obtained this data.”

It’s difficult to know who to believe – on the one hand, AntiSec have produced nothing to back up their claims that the FBI are stalking iPhone users through their UDID codes, but then again, it’s only to be expected that the Bureau would deny holding such information. After all, it’s kind of hard to justify keeping this amount of private data on an overwhelmingly innocent and law abiding section of the population, perhaps even more so when many of them are not even US citizens.

For now, the only thing we can be certain of its that the database has been leaked from somewhere – it’s real – and so iPhone users have every reason to be concerned.