A private security company and the federal government have spent tens of millions of dollars settling legal claims brought by Manus Island guards who were left physically or mentally damaged from riots at the detention centre.

Three more claims were settled by Arnold Thomas & Becker last week, meaning 15 former guards employed by G4S have now been compensated in relation to the February 2014 riots which claimed the life of the asylum seeker Reza Berati.

Seventy-seven people were injured in the riots at the Papua New Guinea centre, including a person who was shot in the buttock and another who suffered a fractured skull.