Top police may have ignored calls for help to deal with hundreds of Wairarapa child abuse cases that languished uninvestigated.

Detective Sue Mackle wrote to deputy commissioner Rob Pope and other senior staff in 2006 saying she was unable to cope with the number of child abuse cases in the district, the Dominion Post reported.

She estimated about 140 cases had not been investigated.

The files were on average five years old with one complaint laid 11 years ago.

Some children remained living with those alleged to have abused them.

Police last month admitted there was a backlog of more than 100 cases and apologised for the "unacceptable" delays.

The Independent Police Conduct Authority was investigating.

In her email Ms Mackle said she was often exhausted and needed more staff to deal with the workload.

"My excessive file load has been widely known at a local level for years (literally) but obviously child abuse is not an area of importance for the police, as opposed to areas such as traffic, which is."

The backlog was highlighted last year with the launch of the District Child Protection Team -- which has since investigated the old files and laid as many as 100 charges.

Police National Headquarters would not comment on Ms Mackle's email, citing the IPCA investigation.

Police Association president Greg O'Connor said the association and officers were putting their faith in the IPCA investigation.