The facility on the Indian Ocean territory some 2,300 kilometres northwest of the Western Australia city of Perth had been the site of riots, deaths and alleged rapes and self-harm since it was opened in 2008.
“The centre has now closed, with around 30 remaining detainees transferred to mainland detention facilities last weekend,” a spokesman for Immigration Minister David Coleman said.
The centre was a key part of Canberra’s efforts to shut down the asylum-seeker smuggling trade, with arrivals sent to Christmas Island or other offshore Pacific camps in Papua New Guinea and Nauru.
At one point, boats were arriving almost daily from departure sites in Indonesia and Sri Lanka carrying desperate migrants from Afghanistan and the Middle East, with some vessels sinking en route.
Under a zero-tolerance policy followed by the conservative government since late 2013, boats were turned back and asylum-seekers were banned from resettling in Australia, eventually choking off the flow of illegal arrivals.
“At its peak in July 2013, there were more than 10,000 people held in immigration detention, including 2,000 children,” Coleman said as he blamed the previous Labour government for the arrivals.
“This government has stopped the boats, stopped the evil people smuggling trade and removed those children from detention.”
The policy was severely criticised by the United Nations and human rights groups amid horror stories of poor conditions, abuse, suicides and despair as some detainees including children languished in detention centres for years.
The Christmas Island camp, which more recently also held non-citizens convicted of crimes awaiting deportation, was the site of a two-day riot in 2015 after the death of an asylum-seeker outside the facility.
Concerns about suicides at the camp had become so serious at one point that staff were reportedly told to carry knives at all times so they could cut down detainees who tried to hang themselves.
The island was also the site of a deadly asylum-seeker shipwreck in December 2010, with estimates of almost 50 people killed as the wooden fishing boat shattered on rocks in a storm.
Only 42 people were rescued before the search for survivors was called off. It was the worst disaster involving an asylum-seeker boat bound for Australia since the sinking of a ship off Indonesia in 2001, when all 353 on board died.
Coleman said the Christmas Island centre would be “kept in a state of operational readiness” so it can be re-opened at short notice if needed.