Jack Steele, 66, a former editor of the Scripps-Howard News Service in Washington and a prize-winning newspaperman whose career spanned more than 40 years, died Wednesday at the Bennington Hospital in Bennington, Vt. He had cancer.

Mr. Steele, who recently was cited by Pulitizer Prize-winning reporter Clark R. Mollenhoff in a new journalism textbook as "the father of modern investigative reporting," worked for the old New York Herald Tribune in New York, the Middle West and in Washington and, from 1953 until his retirement in 1979, for the Scripps-Howard Newspaper Alliance in Washington and elsewhere in the world.

Among the major stories he covered where the Hindenberg dirigible disaster at Lakehurst, N.J., in 1937, the death of President Franklin D. Roosevelt, a series of scandals involving influence peddling and so-called "five percenters" during the Truman Administration, and the war in Vietnam.

His honors included the Raymond Clapper Award for distinguished Washington correspondence, the Heywood Broun Award and the Sigma Delta Chi Award. He also contributed to a Pulitzer Prize won by the New York Herald Tribune. In 1963, Mr. Steele won the Ernie Pyle Memorial Award for his coverage of civil rights developments in Mississippi and Alabama.

Several years earlier, Mr. Steele wrote a series of articles on organizations promoting racial and religious hatred in the United States. When they appeared, the late Speaker of the House of Representatives, John McCormack of Massachussetts, then the House Democratic leader, called them "one of the most constructive pieces of newspaper work I have seen in many years."

But the hallmark of Mr. Steele's work and an important event in modern investigative journalism -- was his series of exposes on the Reconstruction Finance Corp. and the wholesale peddling of influence by so-called "five percenters" during the Truman years. Mr. Truman himself presented him with the Clapper Award in 1949 for these articles.

Mr. Steele was a fomer president and secretary of the Washington Gridiron Club. The club includes some of Washington's most eminent journalists.

Mr. Steele was born in North Manchester, Ind., and grew up in Rockaway, N.J. He was graduated from Middlebury (Vt.) College and the Columbia University School of Journalism.

He was hired by the Herald Tribune while still at Columbia. He worked in New York until 1941 when he was named the newspaper's Midwestern correspondent. In 1944 he was transferred to the Washington bureau, of which he eventually became assistanat chief.

In 1953 he left the Herald Tribune to join the Scripps-Howard Washington bureau. He later was named chief political writer for the Scripps-Howard Newspapers, managing editor of the Scripps-Howard Newspaper Alliance and then editor of the Scripps-Howard News Service. In 1966 he went to Vietnam for Scripps-Howard.

Mr. Steele, who moved to Bennington following his retirement in September, 1979, had held several volunteer posts with the American Heart Association. He was a member of the National Press Club.

Survivors include his wife, Barbara, of Bennington, two sons, Jeff, of Washington, and Peter, of Boston, Mass., and two grandchildren.

The family suggests that expressions of sympathy be in the form of contributions to the American Heart Association, or to the Scripps-Howard Foundation.