Former South Korean sprinter Seo Mal-ku, whose national record in the men's 100-meter dash once stood for more than three decades, died of a heart attack Monday.

He was 60.

An official at the Korea Association of Athletics Federations said Seo passed away in the early hours of Monday.

Seo set the national 100m record with a time of 10.34 seconds at the Summer Universiade in Mexico City in September 1979. The mark was untouched until June 2010, when Kim Kuk-young came in 10.23 seconds.

Kim broke his own record by 0.07 second at the Summer Universiade in Gwangju, some 330 kilometers south of Seoul, in July this year.

In his post-athletic career, Seo served as the head coach of the national athletics team in 2009. He had been a professor in the department of general sports at the Naval Academy.

Seo was a player-trainer for the Lotte Giants, a South Korean baseball club, from 1984 to 1987, but never appeared in a game.

Seo started running as a high school freshman and won his first national title in the 100m two years later.

He actually clocked at 10.30 seconds in the national team trials for the Asian Athletics Championships in 1979, but it wasn't recognized as an official record because he was timed manually.

Then in Mexico City later that year, Seo ran the race in 10.34 seconds for the record. (Yonhap)