Vic prisoner rioted days before release

A prisoner who trashed property during Victoria's worst jail riot was 14 days from being released.

Troy Roseby, 29, was captured on CCTV throwing a computer monitor onto the ground and helping breach a fence at the Metropolitan Remand Centre at Ravenhall in June 2015.

The riot, sparked by a tobacco ban, caused an estimated $12 million damage and lasted some 15 hours before authorities regained control.

Roseby pleaded guilty to one charge of rioting and was sentenced to 15 months in prison at the County Court on Monday.

"It is very difficult to understand why you would have placed your liberty in jeopardy and become involved in this riot," Judge Frances Hogan said, noting the father-of-two had been due for release two weeks later.

Prison officers feared for their lives and many still experience nightmares and flashbacks as a result of the violence, she noted.

"Although you were not one of the organisers, it seems that you were readily caught up and enthusiastically participated in a number of aspects of the riot, and this is how the mob mentality of a riot becomes out of control and so dangerous," Judge Hogan said.

Roseby, whose previous convictions include armed robbery, will serve a minimum of 10 months for rioting.