Remnants of the aircraft's instrument panel, meanwhile, will be shipped to the United States for forensic inspection, Mexican Deputy Communications and Transportation Minister Carlos Alfonso Moran Moguel said at a press conference.
"Many of these parts are not in the best of shape" due to the "intense fire" that consumed the aircraft, said Moran, but "many of the investigators believe they can extract ... important digital information" at specialized laboratories.
The aircraft carrying Mexico's Puebla State Governor Martha Erika Alonso, who was in office for just 10 days, and her husband Rafael Moreno Valle, crashed on Christmas Eve shortly after taking off from a heliport in the state capital, also named Puebla.
Alonso and her husband were prominent members of the National Action Party (PAN), and the tragedy immediately sparked accusations from the political opposition, especially as Alonso's gubernatorial victory was rejected by Mexico's ruling progressive Morena party, which claimed that violence and vote tampering had marred the elections.
President Andres Manuel Lopez Obrador has promised a transparent investigation. Investigators have so far ruled out explosives and fuel tampering, and said that the two pilots were experts.
The Italian-made Agusta helicopter was equipped with engines made by U.S. aerospace manufacturer Pratt and Whitney, Moran said earlier.
Mexico has also requested the help of the U.S. National Transportation Safety Board.