Two convicted murderers from the Waterkloof Four have been rearrested after prison officials saw a video of them dancing and allegedly drinking alcohol in their cell.

Christoff Becker and Frikkie du Preez, were serving a sentence for killing an unnamed homeless man in 2001.

The pair – with fellow convicts Reinach Tiedt and Gert van Schalkwyk – were released on parole from prison on 11 February.

They were rearrested after the YouTube video appeared online because drinking alcohol and using a mobile phone in a cell are both against prison regulations.

Manelisi Wolela, the Correctional Services spokesman, said they were both sent back to prison when reports of the video surfaced. They are being held while officials investigate the alleged party.

He said: "There is nothing new at this stage. The investigation is still continuing."

"The department takes very seriously the allegations about the smuggling of alcohol, having a party and using illegally possessed cameras and/or cellphones."

In the clip, music can be heard and a computer can be seen on a table in the cell. The film shows Becker taking pictures of himself posing in front of a mirror while semi-dressed while flexing his muscles and dancing.

Du Preez can be seen drinking out of a mug while sitting on the toilet, laughing at his companion's antics. A bottle of J&B whisky and Johnnie Walker Red Label can also allegedly be seen in the clip.

The pair were teenagers when they attacked a homeless man in Moreletapark in Pretoria with Tiedt and Van Schalkwyk - beating, kicking and stabbing him to death. They had served less than half of their 12-year sentences before they were paroled on good behaviour.

If the pair are found guilty of trangressing prison regulations, by smuggling prohibited items into their cells, they would likely never be able to reapply for parole.

Tiedt and Van Schalwyk were released from prison and placed under house arrest in December 2011. After widespread criticism, they were sent back to prison in September 2012.