The wreckage has the part number "657 BB" visible, according to photos of the debris.
"From the part number, it is confirmed that it is from a Boeing 777 aircraft. This information is from MAS (Malaysia Airlines). They have informed me," AAP reported the minister as saying.
Martin Dolan, chief commissioner of the Australian Transport Safety Bureau (ATSB), which is leading the search for the missing plane, said the agency was "increasingly confident that this debris is from MH370", AAP said.
"The shape of the object looks very much like a very specific part associated only with 777 aircraft."
Analysis of the part - which is believed to be a section of a plane wing called a flaperon - would begin on Wednesday, along with an examination of parts of a suitcase discovered near the debris, French officials said, according to AAP.
It is expected to arrive in the French city of Toulouse on Saturday, where experts from France's crash investigators BEA will examine the part at an aeronautical centre of the Defence Ministry.
There were also reports that a detergent bottle with Indonesian markings and a Chinese bottle of mineral water were also discovered on the same stretch of beach.
The debris washed up on the French island of Reunion, some 4000km from the oceanic region where MH370 was thought to have gone down in March last year.
Australian Transport and Infrastructure Minister Warren Truss said he remained confident the hunt for MH370 was being conducted in the right area, with wreckage on Reunion Island consistent with currents from the zone team is scouring.
"It's not positive proof, but the fact that this wreckage was sighted on the northern part of the Reunion Island is consistent with the current movements, it's consistent with what we might expect to happen in these circumstance," he said.
Truss added: "We remain confident that we're searching in the right place."
Professor of Coastal Oceanography Charitha Pattiaratchi and colleagues at the University of Western Australia agreed it was likely after they refined their computer modelling following the find, AAP reported
"The computer predictions indicated that it would take between 12 and 18 months for the debris to travel from the current search area in the southeast Indian Ocean to Reunion Island," he said.
Professor Pattiaratchi believes more debris could wash up on Reunion Island, Madagascar, or even the coast of Western Australia, AAP said.
Flight MH370 was travelling from Kuala Lumpur to Beijing when it mysteriously veered off course and vanished on March 8 last year.
An Australian-led search has spent 16 months combing the southern Indian Ocean for the aircraft, but no confirmed physical evidence has ever been found, sparking wild conspiracy theories about the plane's fate.
