LOS ANGELES — A 70-year-old runner whose record finish in the Los Angeles Marathon was tossed over cheating allegations was found dead in a dry, concrete channel of the Los Angeles River, officials said Friday.

Los Angeles firefighters responded to a call at 9:48 a.m. Thursday of a possible jumper above the dry river channel and made the grim discovery.

Frank Meza, a physician and marathon runner, was found in a part of the channel northwest of downtown and was pronounced dead at 10:05 a.m. Thursday, according to Sarah Ardalani, a spokeswoman for the L.A. County Department of Medical Examiner-Coroner.

Meza's wife, Faustina Nevarez, who is also a physician, said she has not learned further details yet.

"I haven’t seen anything else; he's dead," she told NBC News on Friday.

Nevarez called her husband a kind and soft-spoken man with many admirers.

"He has helped numerous people, people who worked with him, people who loved him, people who admired him and they've been breaking down my door" with condolences and sympathy, Nevarez said, her voice cracking with emotion.

Dr Frank Meza JP Vanhoegaerden / Kaiser Permanente

In March, Meza crossed the finish line of the Los Angeles Marathon in 2 hours, 53 minutes and 10 seconds — the fastest ever for a man his age.

But last week, race officials said they erased Meza's run from their records "after an extensive review of original video evidence from official race cameras and security cameras at retail locations along the race course."

"Dr. Frank Meza violated a number of race rules ... including re-entering the course from a position other than where he left it," according to race officials. "The video evidence is confirmed by a credible eyewitness report and our calculation that Dr. Meza’s actual running time for at least one 5K course segment would have had to have been faster than the current 70-74 age group 5K world-record [an impossible feat during a marathon]."

The retired physician denied the cheating allegation, telling the Los Angeles Times on Monday: “I didn’t cut the course."

His wife said bloggers had been mercilessly cruel in attacking Meza since the controversy became known.

"I don’t know why we were being attacked as a family; he kept most of it away from me," she said.

Meza's death stunned the running community.

"We are deeply saddened to learn of the death of Dr. Frank Meza," Murphy Reinschreiber, chief operating officer of the L.A. Marathon organizer Conqur Endurance Group, said in a statement. "Our thoughts and prayers go out to his family.

Derek Murphy, an amateur sleuth who investigates cases of potential marathon cheating, also offered his condolences in a statement.

"I am deeply saddened to learn of Frank Meza’s death," said Murphy, who had been closely monitoring the case. "My heart goes out to his family and friends, and I wish for everyone to be respectful and to keep his loved ones in mind."

Meza had practiced family medicine at Kaiser Permanente in Southern California and company officials said he preached healthy living to his patients.

"As a physician, Dr. Meza cared deeply for his patients and our communities and went above and beyond to serve them," according to statement by Southern California Permanente Medical Group. "He was an ardent believer in healthy living, which was exemplified through his passion for running and the work he did to improve the health and opportunities for the Latino community. Dr. Meza will be missed immensely."

Eric Leonard reported from Los Angeles and David K. Li from New York.