The Schedule 7 powers were recently used by officers at Heathrow to detain David Miranda, the partner of Guardian journalist Glenn Greenwald, who worked with US whistleblower Edward Snowden on security services exposes.
The Joint Committee on Human Rights (JCHR) said the measures, which allow police to download data from mobile phones and laptops, as well as take DNA samples, are so wide as not to be "in accordance with the law".
In its report on the new Anti-Social Behaviour, Crime and Policing Bill, which includes amendments to the powers in the Terrorism Act 2000, the committee says the Government has failed to show a need for the "more intrusive powers".
The group of MPs and peers want a threshold to powers so they can only be applied if the examining officer reasonably suspects the person is or has been involved in terrorism.
The committee's report welcomed changes to the Schedule 7 powers, which narrow the scope of the powers and reduce the potential for them to clash with the European Convention on Human Rights.
However, JCHR chairman Dr Hywel Francis MP said: "We make the simple recommendation that the more intrusive powers should only be available where the police have formed a reasonable suspicion that the traveller may be somebody who is involved in terrorism."