TOKYO (AP) _ Kazuo Tamaki, an administrative official in Prime Minister Yasuhiro Nakasone's Cabinet, died Sunday night, his office said. He was 64.

A spokesman said Tamaki died of ''hepatic insufficiency'' but gave no details. The spokesman spoke on condition that he not be identified.

Tamaki, a native of Wakayama in southern Japan, was a close political ally of Nakasone and had served as his state minister in the Administrative and Management Agency since July.

The agency, established in 1948, is responsible for collecting and compiling statistical information on the Japanese government and also receives public complaints concerning government policies.

Tamaki entered politics when he was elected a member of the House of Councillors in 1972, a post he held for three terms. He served as the deputy chairman of the Liberal Democratic Party's Executive Council before becoming director general of the Management and Coordination Agency.

Tamaki is survived by his wife, Sadako, and two daughters.