Shocked MPs recoiled yesterday from "unlawful" coalition proposals to renew laws letting border police search and detain travellers for hours at a time without any grounds for suspicion.

In a report, MPs from the parliamentary joint committee on human rights said Home Secretary Theresa May had failed to give any good reason for keeping the policy.

Ms May has promised an overhaul of controversial "schedule 7" laws, which give police the power to hold a person passing through Britain's borders for up to nine hours without cause, with no automatic right to legal representation or the right to silence.

Her new legislation would cut that time to six hours, but retains the denial of rights of representation and silence to detainees.

And among the "more intrusive powers" she had retained were the ability for police to search people and their possessions, download any data from electronic devices and take fingerprints and DNA samples - all without suspicion.

"We consider that the current powers to access, search, examine, copy and retain data held on personal electronic devices, such as mobile phones, laptops and tablets, are so wide as not to be 'in accordance with the law'," the committee found.

It added that extracting data from such devices "should only be exercisable on reasonable suspicion,"

Committee chairman and Welsh Labour MP Hywel Francis said recent events - the detention of journalist Glenn Greenwald's partner David Miranda and Baraa Shiban of prisoner rights charity Reprieve - had "brought to the world's attention how extraordinarily broad those powers are."

"Most people would be shocked to know that the police have such extensive powers which could be exercised in relation to anyone, whether suspicious or not."

A requirement of reasonable suspicion of involvement in terrorism was a simple precaution, he said.

The condemnation came as the Independent Police Complaints Commission revealed it would be taking London's Metropolitan Police to the High Court over its refusal to hand over files covering the investigation of complaints made against officers using their powers under schedule 7.

The judicial review was a "direct response" to complaints from Muslim community groups, it said.