The investigation focused on two fibre pieces found near Sainte Luce in southeastern Madagascar in June. The pieces were handed over to Australian Transport Safety Bureau (ATSB) on September 12.
The remains -- which the press had reported were burned -- could not be associated with the missing airplane, said Australian Transport Minister Darren Chester, Efe news agency reported.
"At this stage it is not possible to determine whether the debris is from MH370 or indeed even a Boeing 777," Chester said in a statement.
He further specified they found "no manufacturing identifiers, that provided clues as to the items' origins".
He also stressed that "contrary to speculation, there is no evidence the item was exposed to heat or fire".
Australia is leading the operation, which includes Malaysia and China, to search for the wreckage of MH370 in an 120,000-sq. km area of the Indian Ocean off the Western Australia coast, which is expected to conclude in December.
So far, pieces have been recovered from beaches in Reunion Island, Mozambique, Mauritius, South Africa and the French island of Rodrigues, and the authorities have confirmed the debris to be from the missing plane.
In March 2014, the Beijing-bound Malaysia Airlines aircraft, carrying 239 passengers, disappeared 40 minutes after it took off from Kuala Lumpur after someone allegedly turned off the communication systems of the plane.
The plane is believed to have crashed in a remote region of the Indian Ocean after running out of fuel.
