Four Bradford University students, freed on appeal after being jailed for becoming "intoxicated" by extremist propaganda, could be allowed to return here to study.

The University's vice-chancellor, Professor Mark Cleary, said he would be willing to sit down and discuss the students' return if they wanted to.

The court's ruling has thrown the spotlight on the Terrorism Act under which they were jailed and sparked calls for it to either be clarified or hardened up.

The four Bradford students were arrested after London Muslim schoolboy Mohammed Irfan Raja ran away from home in February 2006.

Lord Chief Justice Lord Phillips, sitting with two other judges yesterday, quashed their convictions and ordered their release.

Raja - who left a note for his parents saying he was going to fight abroad and they would meet again in heaven - now 20, of Ilford, east London, and students Awaab Iqbal, 20, of Grove Terrace, Bradford; Usman Ahmed Malik, 22, of Laisteridge Lane, Bradford, Aitzaz Zafar, 21, of Bishop Street, Rochdale, and Akbar Butt, 21, of Southall, west London, were convicted on July 24 last year of offences of possessing articles for a purpose connected with the commission, preparation or instigation of an act of terrorism, contrary to section 57 of the Terrorism Act 2000.

Following their release yesterday, Professor Cleary said: "On hearing the news of their acquittal, we hope these young men will now be able to rebuild their lives. Should any of them wish to continue their studies at Bradford, we would be happy to discuss this.

"The University of Bradford offers an environment where people are free to learn, study, research and express themselves in a number of ways, including through the societies of our Students' Union. We feel that this judgement upholds those principles.

"However, it appears that these individuals broke University regulations by downloading highly inappropriate material. Whilst it has been successfully argued that there was no terrorist intent behind it, we take issue with any offensive material downloaded using our computers."

Section 57 of the Terrorism Act provides that "a person commits an offence if he possesses an article in circumstances which give rise to a reasonable suspicion that his possession is for a purpose connected with the commission, preparation or instigation of an act of terrorism".

When sentencing, Recorder of London Judge Peter Beaumont said they were preparing to train in Pakistan and then fight in Afghanistan against its allies, which included British soldiers. They were described as being "intoxicated" by propaganda.

Raja was given two years' youth detention, Zafar and Iqbal were given three years detention, Malik was sent to prison for three years and Butt was given 27 months detention.

However, at their trial, the men said they had been uniquely prosecuted for what they had read, rather than anything they had done.

In their hearing before the Court of Appeal yesterday, their defence argued the young men should not have been convicted solely on the allegation that they had downloaded and shared literature off the internet.

All denied having articles for terrorism and said the material, downloaded from various internet sites, was not intended to encourage terrorism or martyrdom. They denied having extremist views and some said they were researching ideology and other matters.

None of the men possessed information which suggested they were plotting a bomb attack.

Allowing their appeals yesterday, Lord Phillips, sitting with Mr Justice Owen and Mr Justice Bean in London, said: "We do not consider that it was made plain to the jury, whether by the prosecution or by the Recorder, that the case that the appellants had to face was that they possessed the extremist material for use in the future to incite the commission of terrorist acts.

"We doubt whether the evidence supported such a case."

Imran Khan, solicitor for Mr Zafar, said the judgment had made it absolutely clear that possession of material must be for intent to use it unlawfully.

Young Muslims seeking to explore the world of their religion should no longer be victimised, he said.

"My client is over the moon. He says it is surreal and he cannot see why he has spent the last two years in prison for looking at material which he had no intention of using for terrorism.

"Young people should not be frightened of exploring their world."

Asked if the judgment might send out the wrong message, Mr Khan said: "There will always be people out there with wrong intentions, but we must not criminalise people for simply looking at material, whether it is good or bad."

He said the Government should look carefully at the judgment and reconsider the current legislation.

"This is a good judgment for the Muslim community and the community at large," he said.

Defence lawyers said later that the effect of the court ruling was that it was permissible to download such material so long as there was no intention to use it.

Usman Malik's solicitor, Saghir Hussein, said later: "This is a landmark judgment in a test case over the innocent possession of materials, including books and speech, and the court has finally agreed that this is in no way connected to terrorism.

"It was very difficult in the current climate for any jury to decide on anything apart from conviction.

"However, a more detached and informed court has recognised the draconian nature of Sections 57/58. This will have implications for other cases, such as those alleging the glorification of terrorism."

A spokesman for the Crown Prosecution Service said: "We will consider the judgement and we have asked for seven days to consider whether to appeal to the House of Lords."

Bradford West MP Marsha Singh, whose constituency includes Bradford University, said: "The was the first conviction on this basis under the Terrorism Act 2000 and obviously the law has to be clarified.

"The Court of Appeal has looked at this and come up with the interpretation that this was just an act of reading literature. I think we should leave it at that."

However, Philip Davies, Conservative MP for Shipley, called Lord Phillip's decision "quite worrying". Mr Davies added: "These judges are giving people a green light to look at material which is totally inappropriate. Given the situation we are in that is quite worrying. Why on earth were these people accessing this material? I think people generally would like to see a harder line being taken."

Speaking to the T&A, Professor Conor Gearty, Professor of Human Rights Law at the London School of Economics, questioned whether a prosecution in this case had been correct.

He said: "Anxieties about terrorism must never be allowed to reach such a point that we feel incapable as a society of engaging in free and frank discussion even with those with whom we profoundly disagree or even with those whose views we loathe.

"It is very important that when we respond to terrorism, or the fear of terrorism, we do so in a proportionate way. Sometimes in telling us this, the courts find that that they have to run counter to our intuition to punish so as better to preserve our long term interest in freedom. If this is what the court of appeal have done in this case, then Lord Phillips and his colleagues are to be applauded."

e-mail: dan.webber@bradford.newsquest.co.uk