HONG KONG — It was a breakthrough in one of the biggest mysteries in aviation history. When a wing part belonging to a Boeing 777 was found last week on the remote Indian Ocean island of Réunion, the world took notice, echoing the intense news media coverage that followed the disappearance of Malaysia Airlines Flight 370 on March 8, 2014.

But in the nation where the ill-fated flight originated, where its crew members were from and whose government owned the plane, the people’s attention was focused elsewhere: on a huge political scandal involving almost $700 million in funds that mysteriously appeared in bank accounts belonging to Malaysia’s prime minister, Najib Razak.

Even Mr. Najib’s solemn announcement in the early hours of Thursday claiming that the wing part, called a flaperon, was “conclusively confirmed” to have been from Flight 370 “looks to have been aimed at bolstering his standing in Malaysia,” said Clive Kessler, an emeritus professor at the University of New South Wales in Sydney, Australia, who has studied Malaysia since the mid-1960s.

As the scandal consumed the nation in July, Mr. Najib went “virtually into hiding” and refused to answer questions about it, Mr. Kessler said.