The British branch of human rights organisation Amnesty International has said that the new Terrorism Act 2000 could lead to breaches of human rights.
A spokesperson for organisation told ireland.comtoday that the new Act puts emergency powers introduced to deal with terrorist activities in Northern Ireland into permanent legislation.
According to Amnesty, the Act shifts the presumption of innocence to the assumption of guilt in situations where an individual has been arrested for the possession of materials that might be used in a terrorist attack.
In effect, the spokesperson said, if someone is arrested in the possession of material that has the potential to do harm, that person must now prove that the material was not intended for terrorism rather than previously, where the prosecution had to prove that it was.
Amnesty UK also expressed "serious concern" over the extension of the stop and search powers given to the police, and the extension of the amount of time a suspect can be held without access to a lawyer from 36 to 48 hours.
"We published our concerns regarding the Act when it was first drafted last April and hoped that Act implemented would address those concerns," said the Amnesty spokesperson said.
"However, many of our concerns - notably the extension of police powers, what we see as a threat to the right to a fair trial, and the possible violations of the right to assembly contained in the Act - have not been addressed.
"This Act effectively takes emergency powers that were conceded to deal with the situation in Northern Ireland and puts them permanently into legislation."
Amnesty also said that it remained deeply concerned about the powers of the act despite assurances from the British Home Secretary, Mr Jack Straw, that the Act would enhance civil liberties.
"We still remain concerned about the implications of the Act and will be watching closely to see how it is used," the spokesperson added.