The law experts said many anti-terror measures breached human rights
Anti-terror measures worldwide have seriously undermined international human rights law, a report by legal experts says.
After a three-year global study, the International Commission of Jurists said many states used the public's fear of terrorism to introduce measures.
These included detention without trial, illegal disappearance and torture.
It also said that the UK and the US have "actively undermined" international law by their actions.
It concluded that many measures introduced to fight terrorism were illegal and counter-productive.
It called for justice systems to be strengthened and warned that temporary measures should not become permanent.
The Geneva-based International Commission of Jurists (ICJ) is a non-governmental organisation which promotes the observance of the rule of law and the legal protection of human rights.
The panel of eminent lawyers and judges concluded that the framework of international law that existed before the 9/11 attacks on the US was robust and effective.
Lack of safeguards
But now, it said, it was being actively undermined by many states and liberal democracies like the US and the UK.
The report remarks upon the extent to which undemocratic regimes with poor human rights records have referred to counter-terror practices of countries like the US to justify their own abusive policies.
The report will make uncomfortable reading for many in governments on both sides of the Atlantic, says BBC security correspondent Frank Gardner.
The panel said the legal systems put in place after World War II were "well-equipped to handle current terror threats".
It said countries should use civilian legal systems to try suspects and "not resort to ad-hoc tribunals or military courts to try terror suspects".
The report's authors expressed concern at the lack of adequate safeguards in the use of control orders, the weakness of diplomatic assurances in relation to deportations and "excessive detention without charge".
Britain's pre-trial detention time limit of 28 days is one of the longest in the world.
The British Home Office said the UK faced a severe threat from terrorism.
INTERNATIONAL COMMISSION OF JURISTS
Promotes understanding and observance of international law and principles that advance human rights
Founded in Berlin in 1952
Comprised of up to 60 lawyers, including senior judges, attorneys and academics
Reflects geographical diversity of the world and its many legal systems
Current president is Mary Robinson, former Irish president and UN Human Rights Commissioner
"We recognise clearly our obligations to protect the public from terrorist atrocities whilst upholding our firm commitment to human rights and civil liberties," it said in a statement.
"Our policies strike that balance, with new legislation facing rigorous scrutiny through external consultation and in Parliament as well as being subject to the Human Rights Act, which the UK government enacted."
The ICJ report recommended an urgent review of counter-terrorism laws and policies to prevent serious and permanent damage to fundamental human rights principles.
Fear of terrorism
The panel reviewed counter-terrorism measures in over 40 countries, and heard from government officials, victims of terror attacks, and from people detained on suspicion of terrorism.
It found that many states have used the fear of terrorism to introduce measures which are illegal such as torture, detention without trial, and enforced disappearance.
Some of the world's top international law experts served on the ICJ panel, including Mary Robinson, former president of Ireland and former United Nations human rights commissioner, and Arthur Chaskelson, former president of the constitutional court of south Africa.
Mr Chaskelson, chairman of the panel, said: "In the course of this inquiry, we have been shocked by the extent of the damage done over the past seven years by excessive or abusive counter-terrorism measures in a wide range of countries around the world.
"Many governments, ignoring the lessons of history, have allowed themselves to be rushed into hasty responses to terrorism that have undermined cherished values and violated human rights.
"The result is a serious threat to the integrity of the international human rights legal framework."
The report also called on the US administration of President Barack Obama to repeal any policies that were instigated under the "'war on terror' paradigm" that were inconsistent with international human rights law.
"In particular, it should renounce the use of torture and other proscribed interrogation techniques, extraordinary renditions, and secret and prolonged detention without charge or trial," the report recommended.
It added that the US detention centre at Guantanamo Bay should be closed in a "human rights compliant manner", with inmates either released or charged.
President Obama ordered the closure of Guantanamo Bay within hours of becoming president last month, as well as ordering a review of military trials for terror suspects and a ban on harsh interrogation methods.