A former senior Foreign Ministry official testified Friday in the Diet that key documents related to the secret nuclear pacts between Japan and the U.S. that he had filed were missing, and suggested they were deliberately destroyed.

Kazuhiko Togo, a former Foreign Ministry Treaties Bureau chief, and three others were called to give unsworn testimony before the Diet.

This is the first time witnesses have been called to testify about the nuclear deals, which the government routinely denied existed until the Democratic Party of Japan last year ousted the long-ruling Liberal Democratic Party and the new administration ordered a probe into the pacts.