The Auditor-General has released a report Collecting and using information about suicide, and notes that from 2010/11 to 2014/15 there has been a 60% rise in the time taken to complete coronial inquiries into suicide without an inquest and a 15% increase in the time taken to complete inquiries involving inquests.

The report says the coroners and the Ministry of Justice recognise that they need to complete all coronial inquiries more quickly and have introduced workflow targets to help with this.

In the 2014/15 year, it took an average of 778 calendar days to complete suicide inquiries with an inquest (up from 676 days in 2010/10) and an average of 509 calendar days to complete suicide inquiries without an inquest (up from 318 days in 2010/11).

"To help achieve the targets, the Ministry of Justice is working to set timeliness benchmarks for the parts of inquiries that are within its influence or direct control," the report says, noting that the ministry says it is "early days" for this work.

The Auditor-General report says it supports the ministry's aim of completing inquiries more quickly so that the bereaved can get a timely decision, the Ministry of Health can publish suicide and other mortality statistics sooner, and mortality reviews can be completed.

It also notes that for coroners to find that suicide was the cause of death, they must be sure that the person intended to end their life and that all other explanations have been ruled out.

"Coroners collect information for this purpose. The information is mainly held in physical case files, which makes it more difficult to analyse groups of cases."