A boat carrying about 150 suspected asylum seekers capsized off Australia's Christmas Island and four bodies have been recovered by rescuing ships, Australian Customs and Border Protection Service confirmed on Tuesday.

"Four deceased persons were recovered" while two Australian navy vessels, HMAS Warramunga and HMAS Albany, rescued 144 people from the water, the Customs and Border Protection Service said in its media release.

The boat had first made a distress call but poor weather conditions and the size of the vessel had prevented authorities from HMAS Albany boarding the boat.

HMAS Warramunga later joined HMAS Albany in escorting the vessel to Christmas Island. While the vessel was being escorted it capsized 70 nautical miles off the island, northwest of Australia's mainland.

According to initial reports, a large number of people fell into the water. Few people on board were reportedly wearing lifejackets at the time, with a Royal Australian Air Force plane, a P3-Orion maritime patrol aircraft, dropping life rafts to those in trouble.

About 150 people were on board based on an assessment of information provided by the vessel's crew. This number has been revised downwards from an initial estimate of up to 180 people.

The authorities suspended the search for survivors at 9.38 p.m. Australian Eastern Standard Time (11.38 am GMT),Customs and Border Protection Service said.

Since August 2012, an estimated 44,000 people have arrived in Australia by boat. The number is increasing at an average rate of 2,000 per month.