DES MOINES, Iowa (AP) _ Robert Helmick, a former U.S. Olympic Committee president who resigned amid conflict of interest allegations, died Tuesday at 66.

Helmick died of cardiac failure at Iowa Methodist Medical Center, spokeswoman Angie Fagervik-Chia said. He had a stroke last weekend, law partner David Claypool said.

Helmick, a Des Moines lawyer, was USOC president from 1985 to 1991. He resigned as USOC president and as a member of the International Olympic Committee in 1991 after he was accused of using his position for personal gain.

A USOC investigation into accusations of influence peddling by Helmick found no wrongdoing. Helmick said he resigned because the issue was disruptive to the committee.

Helmick headed the water polo team at the 1972 Munich Games, where 11 Israeli athletes were killed. He called the terrorist attack a ``horribly traumatic event.''

He was in charge of swimming at the 1984 Olympics in Los Angeles and served as president of FINA, the international governing body of swimming, from 1984 to 1988.

``In this moment of sorrow, FINA expresses its deepest condolences to his family and to the USA swimming family, for whom he had worked so much during his life,'' FINA said Tuesday.

The 1991 inquiry that led to his resignation found that Helmick has ``repeatedly violated conflict of interest provisions of the USOC and created a perception that he was trafficking on his Olympic positions for the benefit of his private clients.''

His clients included sporting goods companies, a broadcasting company and others with business interests tied to the Olympics.

The report never was formally adopted by the USOC or the IOC. Helmick, who at the time acknowledged errors in judgment but denied any profit from his Olympic positions, said he had been vindicated. He continued to serve on the USOC.

Helmick was a founding partner of Dorsey & Whitney, a public finance firm.

``He had a great creative mind,'' Claypool said. ``His goal was always to try to find a way to do something rather than not do it. He used his talents in that regard.''

Helmick most recently helped the state of Iowa administer its share of the multistate tobacco settlement. Among his other clients, Claypool said, were cities, counties and school districts.

``He was a man of very good humor, always enjoyed going out for a beer, great sense of humor,'' Claypool said.

Helmick is survived by his wife, Georgia, sons John Helmick and Rob Helmick and daughters Stephanie Ormsby and Suzanne Book.