Aamer Anwar

Mr Anwar told the Sunday Mail that the revelations from the ongoing inquiry into the death of Sheku Bayoh could only be described as “an intrusive abuse of the fundamental right of lawyers to represent their clients without fear or favour”.

William Little, a senior investigator with the Police Investigation and Review Commissioner (PIRC), told the inquiry that an investigation had uncovered the gathering and retention of intelligence on Mr Anwar.

When PIRC pressed the force on the legal basis for doing so, it “hit a kind of block” and was denied further information.

The intelligence operation “would appear to be linked to his employment as a criminal lawyer and his activities as a campaigner for human rights,” Mr Little told the inquiry.

Mr Anwar said: “I do appreciate there may have been occasions that police had a lawful purpose for intelligence gathering, such as when I faced death threats from extremists, but anything that targeted my legitimate activity as a campaigning lawyer or representation of Sheku’s family is unjustified and wholly illegal.

“Had it not been for the public inquiry, we would have been none the wiser. The scale of the checks really begs the question what were they up to, as soon as the Crown discovered any alleged criminality, it should have set off alarm bells.”

A spokesperson for Police Scotland said: “It is vital that the role and independence of the public inquiry is respected to ensure the application of the rule of law, due process, and justice being served.

“Police Scotland will continue to participate fully in an open and transparent manner.”