Chief Coroner Judge Neil MacLean says care must be taken when comparing New Zealand suicide statistics with those of other countries.
Judge MacLean is due on Friday to release provisional figures for self-inflicted deaths to the end of June this year.
Last week, a Mental Health Commission report stated that in 2008, the suicide rate for girls aged 15 to 19 was the highest in the OECD.
Judge MacLean says while New Zealand's systems are now very transparent, the data produced by many other jurisdictions is not as accurate.
He says this is often due to families, for cultural or legal reasons, not wanting a death to be described as suicide.
More on this can be heard on Insight on Sunday.