Mr Ayub said the science ban was one of many 'onerous' restrictions

The Iraqi national, who can only be named as "AE", was told his studies broke an anti-terrorism control order, said the man's lawyer.

Mohammed Ayub said the restriction was pointless as any knowledge in a science class was already in the public domain.

The Home Office said it was not prepared to comment on the case.

Neurotoxins

A Home Office spokesman said: "This is subject to an appeal. Until this is concluded it would be inappropriate to comment any further."

Mr Ayub said he informed the Home Office as a matter of routine when his client, who is in his early 30s, began the secondary-level courses in biology and chemistry at a college in early September.

Mr Ayub said he did not expect there to be a problem, not only because the information is freely available, but because his client had been a medical student in Iraq and would not be learning anything new.

Mr Ayub said: "You could, in fact, if you are determined, pick this up from a library and in fact even more. So we think this is a very narrow and blinkered view.

I'd say that there's very little in the chemistry course that would help a terrorist act

Colin Osborne, the Royal Society of Chemistry

"Are we going to stop people on control orders going to libraries, or going into WH Smith, or Waterstone's?"

Mr Ayub said AE fled his country in 2001 and started the course in order to better occupy his time after the control order was imposed in 2006 and it became impossible to work.

Colin Osborne, head of education at the Royal Society of Chemistry, told Nature magazine: "I'd say that there's very little in the chemistry course that would help a terrorist act."

However Mr Osborne said there were selected elements that might be useful for a terrorist, such as the detailed examination of neurotoxins in the human-biology course.

Mr Ayub said the control order included "numerous" restrictions, including a 16-hour curfew, restrictions on movement, meetings, and use of mobile phones and the internet.

Undisclosed evidence

Mr Ayub said the Home Office had not made it clear exactly what AE was suspected of doing.

He said: "This, dare I say, is the unusual nature of a control order. They don't disclose the specifics, but what they will say is that he may have been involved in terrorist activities. They won't disclose any more than that."

The Home Office spokesman said a control order can be imposed "on anyone the secretary of state has reasonable grounds for suspecting is involved in terrorism or terrorism-related activities.

"And when he or she considers it necessary for the protection of members of the public."

Control orders were introduced as part of the Prevention of Terrorism Act in 2005, and there are currently 14 in force.

A ruling on AE's case is expected in the spring of 2008.