NSW govt seeks to keep prisoner locked up

A 28-year-old man could become the first person in NSW to be kept behind bars beyond their jail term under the state's tough anti-terror laws.

Attorney-General Mark Speakman on Thursday confirmed an application has been lodged for a "continuing detention order" for the offender, whose sentence expires on June 20.

He cannot be named for legal reasons.

The government can apply to keep people locked up if they believe they "pose an unacceptable risk of committing a serious terrorism offence if not detained or supervised beyond the expiry of their sentence".

It is up to the Supreme Court to decide whether to grant the request.

Earlier this year, the government applied for an extended supervision order against Muslim convert Greg Ceissman, 24, under the same new laws.