An investigation has been launched into a NSW correctional centre after a video was uploaded to YouTube from within the prison by a prisoner.

The video shows the man in possession of a knife, a “slasher” and the drug ice – as well as the mobile phone which was used to record and upload the video.

The prisoner describes the centre as a “dead-set joke” and alleges the mobile phone and drugs were brought into the prison by guards.

A spokeswoman from Corrective Services NSW says the incident at the Parklea Correctional Centre is being regarded as a “very serious breach of security” and a multi-team investigation will commence.

The allegations that contraband is being smuggled in by corrections staff will be “immediately investigated”.