Former Finance Minister Kaoru Yosano, known as one of the top policy mavens among lawmakers, has died, an employee of his office said Wednesday. He was 78.

The office declined to comment on any details, including the cause and exact date of his death, citing the Yosano’s will. Details will be announced later after a private funeral, the employee said.

Yosano, a former Lower House lawmaker from Tokyo, had battled cancer, several times since 1977.

He was serving as the chief Cabinet secretary in 2007 when then-Prime Minister Shinzo Abe cut short his first term in office because of health problems.

Yosano “has made great contributions to Japanese politics and government for years,” Chief Cabinet Secretary Yoshihide Suga told reporters Wednesday when asked for comment.

“He had thorough knowledge of a wide range of policy affairs, in particular finance,” he said.

Yosano was known as a fiscal hawk, advocating an increase in the consumption tax rate.

A graduate of the University of Tokyo, Yosano was elected to the Lower House 10 times. He retired from politics in 2012 when throat cancer prevented him from running in the election that year.

He was a grandson of the late Tekkan and Akiko Yosano, both well-known poets. Akiko was particularly famous for her anti-war poem asking her brother not to die in the 1904-05 Russo-Japanese War.