According to the Times newspaper on Wednesday, Home Secretary Charles Clarke is to allow a dozen detainees - some of whom have been imprisoned for three years without trial - to be released while arrangements are made to deport them to their home countries.
Clarke had little choice after Britain's top court ruled in December 2004 against the detention of nine of them, it said.
The British paper said the men could be electronically tagged and let out as early as Wednesday and quoted a senior source as saying: "This has not been easy and it is fraught with legal problems."
A Home Office spokesman confirmed Clarke would respond to the court's ruling in parliament on Wednesday, but declined to give any details of the announcement or comment on the Times report.
After the December court ruling, the government said it would send back to parliament the controversial law under which the Muslim men were held.
But it refused at that time to release them, citing security reasons.
The suspects were detained under laws brought in after the 9/11 attacks in the US.
They gave police the power to detain indefinitely, without trial, foreign nationals suspected of being involved in terrorist activities.