Malaysia Airline passenger jet parked on the tarmac at the Kuala Lumpur International Airport.

Australian search officials said on Thursday they had finished searching an area near where four acoustic signals thought to be related to a missing Malaysian jetliner had been picked up, and had now discounted it as the final resting place of the plane.

Authorities narrowed the search for the missing Malaysia Airlines jet last month after picking up a series of pings near the site where analysis of satellite data put the last location of the plane some 1,600 km (1,000 miles) off Australia's northwest.