A rookie in the country's top baseball league was found dead Tuesday during the league's rookie seminar, officials said.

The Korea Baseball Organization (KBO) said a first-year player for the Doosan Bears, identified by his surname Lee, was found dead around 9 a.m. on Tuesday on stairs leading to the basement of a condo at Yesan, South Chungcheong Province, about 130 kilometers south of Seoul.

The KBO began its annual rookie seminar at the condo on Monday with 140 new players.

A KBO official said local police are investigating the case and will do an autopsy to determine the exact cause of death.

According to the KBO official, police suspect that Lee, 22, lost his footing in the stairwell while intoxicated.

"Based on testimonies from other players, Lee was last seen on the sixth floor of the condo," the official said. "Police are trying to see how his body was found in the basement."

The officials said players were lodged in rooms on the third to sixth floors.

On Monday, two former KBO managers, Yang Sang-moon and Kim In-sik, offered advice on player conduct on and off the field. On Tuesday, the league was scheduled to hold lectures on doping and illegal gambling.

Lee, a left-handed outfielder, was selected by the Bears in the third round of the annual draft in August of last year. (Yonhap News)