WHO GETS SENT TO CHRISTMAS ISLAND DETENTION CENTRE:

* Asylum seekers deemed a risk to the community who seek to come to Australia for a health assessment under new medevac laws will be sent to Christmas Island.

* This includes those accused of murder, sexual assault of children, violent assaults and planning terrorist attacks.

* The new rules cover 57 men on Manus and Nauru.

* The asylum seekers will be transferred to the island unless they need specialised treatment that can only be provided on the Australian mainland.

* Asylum seekers will go to North West Point, one of three immigration detention facilitates on the island.

* The centre was mothballed in October last year.

* Reopening the centre will cost an estimated $1.4 billion over four years.