Australia's Transport and Infrastructure Minister Warren Truss has said there is a distinctive marking on the piece of debris found on Reunion Island.
He said the number on the part, BB670, could be a maintenance number, but is not a serial number.
Australian scientists were "looking at the photographs to see whether the barnacles on the wreckage reflect the amount of time that it would've been in the water", he said.
"Clearly if this is wreckage from MH370 it's an important breakthrough, particularly for families," Mr Truss added.