Investors in the company that runs Australia's secretive refugee camps are starting to flex their muscles in a way that may achieve what refugee advocates and politicians have failed to for years — greater transparency and oversight.

Australia's offshore immigration detention system, which involves intercepting refugee boat arrivals and processing applications for protection visas on islands outside the migration zone, has earned the criticism of the United Nations because of near-nonexistent access for outside observers.

Transfield Services Ltd., which operates the camps, told local media it would consider taking fund managers to its centers on the Pacific island nation of Nauru and Papua New Guinea's Manus Island — an offer that activist groups say they have been denied since 2012.