A Mongrel Mob inmate stabbed an officer 12 times in the face in a harrowing assault at Hawkes Bay prison yesterday, the Herald understands.

It is the second vicious shanking attack in Kiwi prisons this month and comes amid rising violence in the Corrections system, coupled with a serious staff shortage.

The attack at Hawkes Bay Regional Prison happened some time on Wednesday, and it is understood the attack involved an inmate with a reputation for violence, who is a member of the Mongrel Mob.

Corrections has been approached for comment.

On Friday June 10, an associate of notorious international biker gang the Mongols attacked a Corrections officer with a sharpened toothbrush at Spring Hill prison in Waikato.

Corrections officers at Spring Hill prison in Te Kauwhata were preparing to unlock the man for recreation time when he attacked one staff member while still handcuffed, prison director Scott Walker said.

He then stabbed the staffer with a sharpened plastic toothbrush handle, a commonly used improvised weapon in prisons.

There were 909 assaults of varying severity committed against Corrections staff in the year to May, a percentage increase of 156 per cent from the 355 assaults in 2013.

That resulted in more than 6200 workdays being lost over that period as staff recovered from their injuries.

The frequency of assaults has risen even whilst the prison population has regularly declined since 2018 - dropping to 7927 from 10,540 four years ago.