A patient whose mystery illness sparked a hospital alert in which four men were arrested under the Terrorism Act has died, police said last night.

The 28-year-old attended Stafford General Hospital last month where his condition and the behaviour of four men with him caused medical staff to become suspicious.

They alerted Staffordshire Police who sent in armed officers to detain the four men on a car park at the site.

A force spokeswoman said that the man, Imran Quereshi, from Weston Road, Stafford, who was transferred to Nottingham City Hospital, died on Monday night.

She said: "There are no suspicious circumstances surrounding his death. The police and hospital are unable to confirm the cause of death."

The spokeswoman also confirmed that the force was continuing to support Mr Quereshi's family and friends and that arrangements were being made to fly his body back to Pakistan.

Meanwhile, the four men who were arrested and kept in custody for two days have said they had concerns about the way the investigation had been conducted and were considering their options.

In a statement released last week, the men, aged between 24 and 30, said they hoped lessons had been learned from their "traumatic experience".

Their detention was criticised by Lord Carlile, the Government's independent reviewer of terror laws, who urged the Chief Constable of Staffordshire Police to apologise to the men and order an independent inquiry into his officers' use of the legislation.

Staffordshire Police said its investigation had found no links to terrorism and thanked the men, who face no further action, for their "help and understanding".