A special branch officer has admitted he may have inadvertently contaminated evidence in a terror trial.
Mr Siddique was stopped by detectives at Glasgow Airport
Det Con Gary Murray said he breached guidelines by switching on a laptop belonging to student Mohammed Siddique after stopping him at Glasgow Airport.
The High Court in Glasgow was told Mr Siddique was detained as he prepared to fly to Pakistan with his uncle.
Mr Siddique, from Alva, Clackmannanshire, denies five charges under the Terrorism Act 2000.
Det Con Murray, who gave his evidence from behind screens, said Mr Siddique was held at 1850 BST on 5 April last year in the international departure lounge together with his uncle Mohammed Rafik.
He said that he and his colleagues had earlier been ordered to detain Mr Siddique, whose luggage and that of his uncle was taken off the plane.
Mr Siddique was questioned for five hours by the detectives. His luggage contained 22 compact discs which he said contained Arabic poems, a mobile phone and a laptop computer.
Det Con Murray admitted that he switched on the computer after being given the go-ahead by a more senior officer, and examined it over the course of 70 minutes.
Brain McConnachie QC, prosecuting, asked: "Did you find anything relating to terrorism?"
Det Con Murray replied: "No."
He said that he had opened a number of icons but found nothing relevant to "other inquiries."
Det Con Murray admitted to Mr McConnachie that according to guidelines he should not have switched on the laptop, but he was not aware of that instruction at the time.
Mr Siddique was arrested in Alva in April last year
Det Con Murray said that he did not connect the laptop to the internet or insert any DVDs, and said he had not planted any evidence or deleted any information.
Mr Siddique was later allowed to leave the airport. His uncle, who was interviewed separately, was also permitted to leave.
Both missed their plane, which had taken off hours earlier. They had been due to fly to Pakistan for three months.
Mr Siddique, of Alva, Clackmannanshire, was arrested at his family home in a police operation on 13 April 2006.
The trial was told Mr Siddique was manacled by cable ties during the dawn raid.
Det Con John Hay told the court how colleagues from Central Scotland police used a battering ram to break into the seven bedroom home at Myretoungate, Alva, at about 0700 BST.
The detective said: "When we got there people within the home had cable ties around their wrists.
"I just saw Mohammed Siddique and his brother. Mohammed was sitting on a bed. He had cable ties on his hands to the back."
Det Con Hay said he later accompanied Mr Siddique to Govan Police Station in Glasgow, where he was to be detained. A request by Mr Siddique to be allowed to telephone his father was refused by a senior officer.
Mr McConnachie asked the officer: "Are you of the opinion that police have to carry out procedures that seem unpalatable in the cold light of day?"
Det Con Hay replied: "Yes."
Mr Siddique has been accused of possessing suspicious terrorism-related items including CDs and videos of weapons use, guerrilla tactics and bomb-making.
He has also been accused of collecting terrorist-related information, setting up websites showing how to make and use weapons and explosives, and circulating inflammatory terrorist publications.
A further charge of breach of the peace relates to claims that he showed students at Glasgow Metropolitan College images of suicide bombers and terrorist beheadings.
This charge also includes the allegation that he threatened to become a suicide bomber, and claimed to be a member of al-Qaeda.
The trial, before Lord Carloway, continues.