No charges will be brought against 12 men seized in raids aimed at foiling a suspected al-Qaeda plot in the UK.
The timing of the raids had been brought forward due to a security breach.
The men, 11 Pakistanis and one British man, were arrested around northwest England on 8 April as part of an operation against what Prime Minister Gordon Brown had described as a 'very big terrorist plot'.
All the suspects, aged between 22 and 38, have now been released without charge.
11 of the men have been handed over to immigration officials and now face deportation on national security grounds.
Prosecutors said there was insufficient evidence to justify holding them any longer or bringing charges.
'As there are ongoing issues of matters of national security around this investigation, it does limit what we are able to say,' said Chief Constable Peter Fahy.
'We had a duty to act to protect the public and a subsequent duty to investigate what lay before us. We don't take these decisions lightly and only carry out this kind of action if it is wholly justified.'
The raids were mounted several hours ahead of schedule after a blunder by then counter-terrorism commander Bob Quick.
A document on the operation was photographed as Mr Quick carried it to a briefing at 10 Downing Street, threatening the secrecy of the raids. Mr Quick resigned a day later.
Media reports at the time said police believed a large attack in Britain was in its final stages.
Mr Brown angered Pakistani officials after the arrests by calling on Pakistan to do more to 'root out the terrorist elements in its country'.
Pakistan's ambassador to Britain, Wajid Shamsul Hasan, responded by saying Britain should do more by allowing Pakistan to scrutinise people applying for visas.
