Full statement from Tony Abbott on the search:
“I would like to inform the house that new and credible information has come to light in relation to the search for Malaysia airlines flight MH370 in the southern Indian Ocean."
“The Australian Maritime Safety Authority has received information based on satellite imagery of objects possibly related to the search.
“Following specialist analysis of this satellite imagery, two possible objects related to the search have been identified.
“I can inform the house that a Royal Australian Air Force Orion has been diverted to attempt to locate the objects. This Orion is expected to arrive in the area at about this time. Three more aircraft will follow this Orion. They are tasked for more intensive follow-up search.
“I have spoken to my Malaysian counterpart … and informed him of these developments. I should tell the house – and we must keep this in mind – the task of locating these objects will be extremely difficult and it may turn out that they are not related to the search for flight MH370. Nevertheless, I did want to update the house on this potentially important development.”
A New Zealand Orion is taking part in the search for the objects spotted in the Indian Ocean. It is due to arrive in the area around 8pm local time.
The Australian Maritime Safety Authority (AMSA) revealed the imagery had been captured by its rescue coordination centre.
It indicates debris near the search zone in the Southern Indian Ocean, some 2300 kilometres southwest of Perth.
"They may not be related to the aircraft,'' an AMSA statement said.
AMSA has said that the conditions in the area where the debris has been spotted are difficult and that visibilty is poor.
A RAAF aircraft arrived at the area just before 2pm (AEDT) and three more military aircraft, including two from the United States and New Zealand, are expected to reach the area later this evening.
An Australian Hercules will drop marker buoys in the area highlighted by the satellite imagery
The marker buoys provided information about water movement to assist drift modelling.
"They will provide an ongoing reference point if the task of relocating the objects becomes protracted,'' AMSA said.
Weather conditions in the area are moderate but visibility is poor.
"It is the best lead we have so far" in the search for the missing plane says Australia's Maritime Safety Authority.
The AMSA is working to provide imagery of the area.
The debris spotted is around 24 metres in size.
A merchant ship that responded to a shipping broadcast issued by Rescue Coordination Australia on Monday is expected to arrive in the area about 6pm (AEDT).
John Young, emergency response division general manager at AMSA, said the focus was to continue the search with all available ships and aircraft.
"The objects are relatively indistinct on the imagery,'' he said.
"The are objects of a reasonable size and probably awash with water.''
The largest was assessed as being about 24 metres.
Mr Young said the ocean in the area was thousands of metres deep.
"AMSA is doing its level best to find anyone that might have survived,'' he said when asked what advice he had for families of the 239 people who were on the missing flight.
Mr Young cautioned the objects would be difficult to locate.
"It's probably the best lead we have right now but we have to get there, find them, see them, assess them, to know whether it's really meaningful or not,'' he said.
AMSA is concentrating in that area for now because it wants to find the objects and it wants to work out what they are.
Mr Young said in AMSA'S experience there was usually debris floating out in that area, but on this occasion the size, and the fact that there were a number, made it worth looking at.
He cautioned against any hasty expectations of an outcome of the search because of unfavourable weather conditions.
"We may get a sighting, we may not. We may get it tomorrow, we may not,'' he said.
``But we will continue to do this until we locate those objects or we are convinced that we cannot find them.''
The search area is around 2,500 kms southwest of Perth.
Malaysia Airlines has briefed the families about the information provided by the Australian government, a spokeswoman for the airlines told CNN. The airline said unless there is confirmation that the objects in the southern Indian Ocean are that of MH370, they are not sending any families members to Australia.