Four men held under the Terrorism Act for two days after a security alert at a hospital should receive an official police apology, a key Government adviser on terrorism has said.
The four men, aged between 24 and 30, were arrested after a security alert at a Staffordshire hospital when medical staff became concerned about the illness of a fifth man.
After two days in custody, the four men were released without charge on Friday night.
Staffordshire Police said it had found no links to terrorism and thanked the men for their "help and understanding".
Lord Carlile, the Govern-ment's independent reviewer of terror laws said the chief constable should now apologise to the men and order an independent inquiry into his officers' use of the legislation.
"The most important thing is if there has been an error there should be fence-mending at once and it starts with an apology," Lord Carlile said.
"People should not be arrested under the Terrorism Act unless there is a real terrorism issue."
A force spokesman confirmed that the men - who were detained at Stafford General Hospital last Wednesday night- would face no further action.
Police were summoned to the hospital late on Wednesday due to the "suspicious behaviour" of the men.
The four - aged 24, 26, 27 and 30 - were detained after staff contacted police with concerns they had about a fifth man they were accompanying, who was suffering from an unknown illness.
The 28-year-old, who was moved to another hospital for specialist treatment and further tests, remains in a "very poorly" condition.
The force said later that senior officers were aware of Lord Carlile's comments and would be meeting members of the four men's families early next week to discuss the fallout following the arrests.