Organised crime groups are plotting to steal from Indigenous communities that survive on multi-million dollar mining royalties and land use agreements, an eight-year Australian Crime Commission investigation into isolated and trouble-plagued regions has revealed.

The explosive internal report, released under Freedom of Information laws, also found that widespread child sexual abuse in remote Indigenous communities is sometimes excused because of "traditional beliefs".

Issues raised by taskforce remain a major cause for concern: Minister for Indigenous Affairs Senator Nigel Scullion. Credit:Alex Ellinghausen

Prominent members of some communities are suspected to be child sex offenders, or to have protected offenders, and may also be responsible for drug trafficking, fraud, and stealing money from support organisations, where they hold positions of authority, for gambling.

Alcohol and marijuana abuse remain at horrific levels, the report found, but some communities have also recently recorded their first fatal overdoses from pharmaceuticals, including the painkiller Fentanyl.