Russ Conway, whose exposé s in a Massachusetts newspaper uncovered corruption by the leader of the National Hockey League’s players’ union and led to his convictions for fraud, died on Tuesday at his home in Haverhill, Mass. He was 70.

His lawyer, Peter Caruso, confirmed the death. He said Mr. Conway received a diagnosis of heart disease a few years ago.

In 1991, after covering the Boston Bruins for The Eagle-Tribune, a daily newspaper in North Andover, Mass., for many years, Mr. Conway published a five-part series detailing financial malfeasance by Alan Eagleson, the longtime executive director of the National Hockey League Players’ Association.

Over nearly a quarter-century, Mr. Eagleson had amassed immense influence, not only as head of the union but also as an agent for N.H.L. stars like the Bruins’ Bobby Orr and as the organizer of international tournaments like the Canada Cup.