The Labour Party is alleging the government is trying to cover up hundreds of incidents at a youth justice facility near Christchurch.

It says there have been about 600 dangerous incidents at Te Puna Wai o Tuhinapo in Rolleston over the past year.

The facility is a lock-up run by Child Youth and Family.

Labour justice spokesperson Jacinda Ardern said Ministers have known about the problems for years.

Between July last year and April this year there were 590 moderate security incidents, and 37 serious incidents. Ardern claims there have been suicide attempts, 27 assaults on staff and property damage.

Ardern says under-funding means staff at the CYFs lock-up aren't properly trained or supported.