One of the UK's most senior judges has raised concerns about anti-terror legislation which gives police the power to stop and question people entering or leaving Britain.
Supreme Court justice Lord Kerr said he had been given no "reasoned justification" for giving officers such powers.
His comments came in a Supreme Court ruling after the Muslim wife of a convicted terrorist claimed that her human rights had been violated when she was stopped under the terms of schedule seven of the 2000 Terrorism Act on arrival at East Midlands airport in 2011.
A panel of five Supreme Court justices today dismissed the claim by Sylvie Beghal - whose husband Djamel Beghal is in jail in France - by a majority of four to one.
The majority concluded that schedule seven powers were "proportionate" and said the questioning and searching of people arriving in the UK was "rationally connected" to preventing and detecting terrorism.
But Lord Kerr, a former Lord Chief Justice of Northern Ireland, dissented.
He said he would have allowed Mrs Beghal's appeal.
"Of course it is true that the threat of terrorism is substantial and should not be downplayed," said Lord Kerr.
"But that undoubted truth should not mask or distort the obligation to dispassionately examine the aptness of measures taken to deal with it.
"If they are to be seen as no more than necessary, the powers under schedule seven must be capable of withstanding scrutiny of their rationale.
"In my view, no reasoned justification has been proffered for investing examining officers with a power to stop, search, question and detain anyone passing through a port and for making those who refuse to answer questions amenable to the criminal law."
He said people who failed to answer questions could be jailed and said the exercise of schedule seven powers was a significant interference with people's right to privacy - protected under article eight of the European Convention on Human Rights.
"A person stopped under this provision is required to answer questions even though they may not have had the benefit of legal advice," said Lord Kerr.
"Individuals may have many reasons why they do not want to answer questions as to their movements and activities. These reasons are not necessarily or invariably discreditable. Some may be apprehensive about answering questions without a lawyer being present or may lack a full understanding of the significance of refusing to answer.
"The fact that they are open to criminal sanction, which could include imprisonment, for failing to answer questions, renders the exercise of these powers a significant interference with Article 8 rights, in my opinion."