A former chief of the state-run railroad management firm, who had been under an investigation for alleged graft, committed suicide early Friday morning pending a prosecution summons, police said.

Kim Kwang-jae, 58, former chairman of the Korea Rail Network Authority (KRNA), jumped to his death off a bridge over the Han River in the eastern part of Seoul at around 3:30 a.m., police said.

The Seoul Central District Prosecutors' Office has been investigating Kim and several other KRNA officials for allegedly receiving bribes from AVT, a railway parts supplier, for favoring the company in project bids.

The former chairman had reportedly been suffering emotionally following a prosecution raid on his home about a month ago. He was to face a prosecution summons over the case.

Prosecutors said they will close the case against Kim in the wake of his suicide.

A former land ministry official, Kim ended his term as the KRNA's chief seven months earlier after labor union officials blasted him for using his government connections to land the chairman post.

Kim is the second former or current KRNA official to commit suicide during the ongoing probe into the country's railroad corruption.

Last month, a senior KRNA official involved in a separate bribery case took his own life as he faced questioning by prosecutors. (Yonhap)