A 12-hour rooftop riot at a prison in Gippsland overnight is believed to have been sparked in part by a change in toothbrushes as a security measure.

Inmates at the Fulham Correctional Centre near Sale were forced to use flexible toothbrushes after fears that hard toothbrushes could be filed down to make weapons, Corrections Commissioner Bob Hastings said.

Hard to reach ... Rioting inmates on the roof of Fulham Prison, where a change to flexible toothbrushes is believed to have sparked fury. Credit:Geoff Parrington

‘‘This is really a safety issue because unfortunately some of the prisoners with the conventional toothbrushes used those to become weapons,’’ Mr Hastings told the ABC radio today.

‘‘There was also some other discussion up around Fulham around a pay TV deal that was about to finish and move to a more digital free-to-air process. There were also some issues around dress standards that people objected to.’’