When postgraduate student Rizwaan Sabir was arrested under anti-terror legislation on suspicion of possessing extremist literature, he thought he would be released in a "couple of hours".
After all, his studies were focused on Islamic extremism and the document that had prompted the police reaction - an edited version of the al-Qaeda training manual - is freely available on the internet.
But rather than being held for a matter of hours, Mr Sabir, along with a member of the university's clerical staff, was held for six days before being released without charge on 20 May.
"I couldn't believe it," Mr Sabir, a politics masters student at the University of Nottingham, told Times Higher Education. "In the next six days, the power of the state hit me as hard as it could. It was sheer psychological torture - particularly in the last 24 hours when they were umming and ahhing about whether to charge me."
Mr Sabir said he had downloaded the 1,500-page document from a site he had found via the search engine Google, in preparation for a PhD on radical Islamic groups.
"If you are doing research for a PhD you need primary sources. I said in my PhD proposal that the strategic approach used by these groups is the most important fundamental area (requiring study)."
Times Higher Education discovered versions of the manual on www.disastercenter.com, a site that gives details of storm, disease and other risks facing the US.
An al-Qaeda training manual - for which the author credit is "al-Qaeda" - is also available from the internet bookseller Amazon.com, priced at $14.95 (£7.55). It is given a rating of one star, out of five, in a review by an Amazon customer who notes: "The information it contains can be found on the internet."
Mr Sabir said he forwarded the document to the staff member who was also arrested, simply because the latter had access to a printer.
The university called in the police after the copy of the manual was found on the staff member's computer. Nottingham said that "there was no reasonable rationale for this person to have that information", as he was not an academic or a student.
"The police were called in on the basis of reasonable anxiety and concern," the university said.
On hearing of the police presence outside the employee's office, Mr Sabir texted him, and was subsequently arrested himself.
Mr Sabir and a number of Nottingham academics have said that the case raises fundamental questions about academic freedom in the midst of government efforts to clamp down on Islamic extremism on campus.
As Times Higher Education went to press, 26 academics at the university had signed a petition calling on the university to uphold academic freedom.
Vanessa Pupavac, a lecturer in international relations at Nottingham, said that Mr Sabir's treatment meant that any academics pursuing "the question of the character of modern-day terrorists" would need to "consider their material" and could risk arrest.
She said she feared that the university would create guidelines limiting academic freedom as a result of the case. "Putting material out of bounds will hinder our understanding of terrorism and our ability to address the problem," she said.
The University and College Union was due to debate the issue at its annual conference this week. Sally Hunt, the union's general secretary, said: "If we really want to tackle problems like extremism then we need to be safe to explore the issues. The last thing we need is people too frightened to research a subject because they fear being arrested."
'A THOROUGH AND SENSITIVELY HANDLED INVESTIGATION': THE University of Nottingham'S STATEMENT
In a statement released to university staff and students, Paul Greatrix, registrar, said:
"The student and staff member were detained in response to a low-key investigation carried out jointly by the Nottinghamshire Constabulary and the West Midlands Counter Terrorism Unit.
"This was a thorough and sensitively handled investigation, which has identified no risks to the campus community or wider public.
"Members of the university can be reassured that we take very seriously our duty to ensure that students and staff are free to study and work in a safe, secure and tolerant environment. There are many ways in which we all work to deliver such conditions and to ensure that everyone is able to enjoy freedom of speech and expression within the law. The university is an open and free arena for debate and dissent.
"One issue to arise from recent events is the level of discussion and guidance on the rights and responsibilities of staff and students in terms of research and freedom of speech.
"There are basic requirements here such as the law relating to incitement of racial hatred and the 1986 Education Act, which relates to freedom of speech in universities.
The University Research Committee is currently considering the enhancement of our research ethics framework.
"The concern here will be to ensure that we are able to provide appropriate protection to those who are conducting legitimate research."