The 27 survivors rescued from a boat that capsized in the Indian Ocean this week have arrived at Christmas Island to undergo medical examinations.
There were 39 people believed to have been on the boat before it capsized 640km north-west of Cocos Island on November 1.
One person has been confirmed dead and 11 are still missing.
The survivors have been placed under mandatory detention at the island's Phosphate Hill detention facility and the construction camp.
"DIAC will, of course, fully cooperate with police and the West Australian Coroner in their investigation into the circumstances of the deaths at sea," a Department of Immigration and Citizenship spokeswoman said.
"The first priority for the department is the health and wellbeing of this group.
"While they appear to be in good physical health, they will now undergo thorough medical examinations to ensure any health issues are quickly identified.
"We are acutely aware this group has recently endured a highly traumatic experience. Appropriate medical treatment and mental health support, including grief counselling, will be available for the 27 survivors on Christmas Island."
The group will also undergo rigorous security and identity checks by security agencies and have their reasons for travel and any claims for protection assessed.
The latest arrivals bring the total number of illegal boat people on Christmas Island to 1151.
The 16 people found off the Tiwi Islands near Darwin on November 4 are en route to the island and are expected to arrive early next week.