An Iranian-Australian man accused of organising an asylum boat that broke up off Christmas Island in 2010, killing about 50 people, has pleaded guilty to people-smuggling charges.

Ali Khorram Heydarkhani faces up to 20 years in jail after admitting four charges, local media report.

The 41-year-old was accused of organising four asylum-seeker boats between 2010 and 2011.

He was arrested in Indonesia and extradited to Australia in 2011.

Mr Heydarkhani had been set for a 12-week trial in Perth, but pleaded guilty to four out of 12 charges after negotiating with prosecutors.