An elderly Christchurch man with advanced dementia was kept locked in a dark room for up to 16 hours a day, trapped in a wetsuit over adult nappies.

Warning: This story details elder abuse that some may find disturbing.

The coroner will not hold an inquiry into the death of an elderly Christchurch man with advanced dementia whose son kept him locked in a dark room for up to 16 hours a day, trapped in a wetsuit over adult nappies.

In findings released on Friday, coroner Mary-Jane Borrowdale stated the cause of 90-year-old Norman Lee's death was pneumonia and severe heart disease with a background of frailty and dementia and a context of elder neglect as a contributing factor.

A coroner's inquiry was opened days after Lee died of pneumonia at Christchurch Hospital on 9 July 2020 but was put on hold while criminal and other investigations were underway.