MEXICO CITY, Dec. 25 (Xinhua) -- International experts have been invited to join the investigation into a helicopter crash that killed two prominent politicians in Mexico on Christmas Eve, the government said on Tuesday.

The crash claimed the lives of five people including the current and former governors of Mexico's central state of Puebla.

The Agusta A109 helicopter carrying Governor Martha Erika Alonso, in office since Dec. 14, and her husband, Rafael Moreno Valle, who served in the post from 2011 to 2017, crashed shortly after taking off in Puebla.

The helicopter was used to provide air taxi service to the couple and the others and on its way to Mexico City.

Deputy Minister of Transport Carlos Moran told a press conference on Tuesday that representatives of the helicopter's Italian manufacturer Agusta and engine maker Pratt and Whitney are already working with the national civil aviation agency at the site of the crash.

In addition, Mexico has requested the help of U.S. National Transportation Safety Board, said Moran.

According to Moran, the aircraft was in good condition and had its paperwork in order.

However, the local control tower reportedly attempted to communicate with the aircraft nine times with no success before it crashed.

The tragedy sparked speculations of wrongdoing by political opposition as Alonso's gubernatorial victory was questioned by Mexico's ruling progressive Morena party, which alleged that the elections had been marred by violence and vote tampering. Alonso and her husband were prominent members of the center-right National Action Party (PAN).