Rosie Ruiz, whose name become synonymous with cheating when Boston Marathon officials vacated her victory in the 1980 race after determining that she had sneaked into it about a mile from the finish line, died last month in Lake Worth, Fla. She was 66.

Her death, on July 8, was not reported widely until a writer for the website LetsRun saw a posting on the site’s message board linking to a funeral home obituary under Ruiz’s name through marriage, Rosie M. Vivas. Cancer was given as the cause of death.

Ruiz was working as a secretary at a commodities trading firm in Manhattan when she stunned the running world by being the first woman to cross the finish line in Boston in 2 hours, 31 minutes and 56 seconds. It would have been the third-fastest time ever recorded by a woman in a marathon.

But suspicions about her victory arose immediately. Spotters had not seen her at checkpoints along the 26-mile course, and after the race she told a television interviewer that she had run only one other marathon, the 1979 New York City Marathon, and that she had finished that race in 2:56:33.