The search for survivors has been called off after a suspected asylum seeker boat capsized off Christmas Island yesterday evening, killing at least four people.

The boat, carrying about 150 people, capsized 70 nautical miles off Christmas Island as it was being escorted by the Australian Navy ships HMAS Albany and HMAS Warramunga.

A total of 144 people were rescued by the naval vessels, but four bodies were recovered from the water.

Customs says crew members from HMAS Albany had tried to board the boat, but failed to do so because the weather was too bad.

Timeline: deadly boat capsize 2:45am: Rescue coordination centre receives phone call from people on the vessel and asks Navy ships to assist. Vessel reportedly stopped with engines not working. Rescue coordination centre issues distress message to shipping in the area to respond. 3:30am: Confirmation that a vessel monitored by HMAS Albany is the same vessel that requested assistance. Albany says vessel showing no signs of distress. 12 noon: Border Protection commands HMAS Warramunga to assist, given the large number identified as being on the boat. 12:05pm: Rescue coordination centre receives more calls for help from people on the vessel. At that time, rescue coordination centre requested Albany to close on the vessel and provide assistance as required. 1:10pm: HMAS Albany closes in to board the vessel. Weather conditions and high sides of the vessel prevented boarding party from getting onboard. Albany reports the vessel appears seaworthy: one engine was working, one was not and the bilge pump was working. 2pm: Warramunga arives on the scene. 2:20pm: Albany commenced escorting the vessel. 6pm: Vessel begins to lean to one side and passengers begin jumping into the water. 6:40pm: Albany reports that the vessel has rolled and capsized. A total of six life rafts deployed by Albany and Warramunga as well as a aircraft overhead. The naval vessels deployed their small boats to assist rescuing the people in the water. 9:20pm: Warramunga had rescued 76 persons, Albany had rescued 68. Four deceased people had been retrieved from the water. 9:40pm: Search suspended. (All times approximate.)

A Royal Australian Air Force P3-Orion maritime patrol aircraft dropped a number of life rafts for the survivors.

Home Affairs Minister Jason Clare told media this morning the Navy was asked to assist the vessel almost 16 hours before it capsized.

"At approximately 2:45am, the rescue coordination centre requested assets to assist after they received a phone call from people on the vessel that it was reportedly stopped in the water with the engines not working," he said.

"At approximately 1:10pm yesterday, HMAS Albany closed in to board the vessel to determine the nature of assistance required. However, weather conditions and the high sides of the vessel prevented the boarding party from getting on board.

"At approximately 6pm, the vessel began to lean to one side and passengers began jumping into the water. At approximately 6:40pm, Albany reported that the vessel rolled and capsized."

The tragedy comes days after nine people, including a baby boy, died at sea when another asylum seeker boat capsized en route to Australia.

Government reviewing asylum seeker policy

Confirmation of the latest fatalities came just hours after Prime Minister Kevin Rudd spoke about some of the challenges posed by people smuggling.

The Federal Government is reviewing Australia's system for processing asylum seekers and Mr Rudd is expected to announce a revamped policy in the next few days.

"If I'm trying to summarise what Australians want, this is what they want: they us to be kind, they want us to be compassionate," he told a community cabinet meeting in Rockhampton.

"But they want an orderly migration system so when we're faced with the challenge of people smugglers, let me tell you, this is really tough."