Only one person has been charged with assault from investigations police conducted into 2000 leaked incident reports from the Nauru immigration detention centre.
Australian Federal Police acting deputy commissioner Justine Saunders told a Senate estimates hearing on Monday 14 incidents had been referred to Nauru police for investigation.
Nine were closed because of insufficient evidence, one complaint was withdrawn and two investigations remain open.
Commissioner Andrew Colvin told the hearing he was confident Nauru police had the capacity and intent to properly investigate incidents involving asylum seekers and refugees on the island.
He acknowledged in the past there had been some deficiencies with Nauru police investigations.
The AFP had undertaken 32 training programs in areas such as seeking victim impact statements and forensic procedures.
Immigration department secretary Michael Pezzullo visited Nauru last week and met with the island's police commissioner.
There were three matters before the magistrate.
The department had carried out a detailed analysis and the majority of the 2123 incident reports were "historical in nature".
The bulk were from welfare services provider Save the Children and 23 were critical incidents, 281 major, 968 minor and 851 unclassified.
Border Force assistant commissioner Kingsley Woodford-Smith said the department was able to match 1527 to its own records.
Immediate and appropriate action was taken in 1460 cases.
