The search for Malaysia Airlines flight 370 is likely to take eight to 12 months, authorities say.

Coordinator of the search, retired Air Chief Marshal Angus Houston, told reporters in Malaysia on Friday that he remained confident that the Boeing 777 would be found in the southern Indian Ocean.

The Bluefin 21, the Artemis autonomous underwater vehicle, will continue searching the ocean bed for MH370. Credit:Australian Defence Force

He said the search would continue because they owed it to the families of the victims and the world to learn what happened to the ill-fated flight.

Mr Houston said last week that authorities would be "doing well" to complete the search in eight months.