LONDON, England (CNN) -- UK security experts have blamed U.S. authorities for compromising an investigation into the alleged trans-Atlantic airliner bomb plot.
A former police anti-terror chief and an opposition lawmaker said the arrest of a terror suspect in Pakistan at the behest of the U.S. in August 2006 meant they were forced to move quickly against 20 suspects in Britain before they could gather sufficient evidence.
This contributed, the experts believe, to a jury's failure on Monday to reach verdicts over prosecution claims that the suspects planned suicide bombings on flights from London's Heathrow Airport to the United States and Canada in 2006.
British prosecutors were on Tuesday considering whether seven of the eight men accused of plotting to bomb the jets should face a retrial. Watch more about the trial »
Three of the men, Abdulla Ali, Assad Sarwar and Tanvir Hussain, were convicted of conspiracy to murder and will be sentenced at a later date.
The jury failed to reach verdicts on four other defendants, Ibrahim Savant, Arafat Khan, Waheed Zaman and Umar Islam. An eighth man, Mohammed Gulzar, was found not guilty on all counts. The remainder of the dozens of men who were arrested have yet to face trial.
Ali, Sarwar and Hussain, pleaded guilty last month to conspiring to cause explosions.
They said they were planning to detonate bombs at key sites as part of a political statement, not with the intent to kill anyone. They maintained that they were not guilty of plotting to blow up airliners over the Atlantic Ocean.
The British Crown Prosecution Service maintained it was a plot -- involving liquid explosives hidden in soft drink bottles -- that could have been pulled off.
It led to new security measures at airports around the world limiting the amount of liquids passengers could take on flights. Watch how the plot changed flying »
British authorities said there was an al Qaeda link to the alleged plot and called it "an ingenious plan to blow up aeroplanes with liquid explosives."
The eight men were arrested in August 2006 when Pakistani security services detained a man in their country allegedly linked to the plot, reportedly at the request of American agencies.
Peter Clarke, the former head of Scotland Yard's Counter Terrorism Command, said British officials had to act quickly following this arrest.
Writing in The Times, he said: "On the evening of August 9, 2006 I was told that a man connected to the British terrorists had been arrested in Pakistan.
"This was not good news. We were at a critical point in building our case against them."
Clarke said Scotland Yard decided "in a matter of minutes" to move against 20 suspects fearing that they could destroy evidence or panic and mount a "desperate attack."
Conservative MP Patrick Mercer, the former shadow homeland security spokesman, told the BBC's Newsnight: "(The suspect), as I understand it, was arrested at the behest of American agencies in Pakistan at very short notice and without telling the British intelligence agencies, without giving them very much warning of what was going to occur.
"As a result of which, a number of operations against our enemies inside this country were not executed to the level that we would have wished.
"There wasn't as much evidence gathered, for instance, as people wanted.
"And, as a result, I know for a fact that a number of military agencies felt that, with more consultation, they would have been able to get more evidence and that actually a number of their operations came close to being compromised."
He added: "What seemed like a very open-and-shut case clearly is not."
The trial began at London's Woolwich Crown Court in early April and the jury began deliberating in late July.
Prosecutors will have until October 3 to decide if they want to retry any of the defendants on the charges for which the jury could not reach a verdict.
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