A man understood to be an Iranian national aged in his late 30s has died in the Villawood Detention Centre in Sydney.
The death was confirmed by the Australia Border Force, who said the matter has been referred for investigation, including by the coroner.
"We express our condolences to the man's family and friends," a spokesperson said on Saturday.
"As this matter will be subject to ongoing investigation, it would not be appropriate to comment further."
The man's age and nationality were provided by the Refugee Action Coalition, which had been told he had not left his room for the past two weeks and was found dead about 1pm on Saturday.
He had been detained in Villawood for two years, it said.
Australian Associated Press
Sign up for our newsletter to stay up to date.