ULSAN, June 19 (Yonhap) -- An internal audit by Hyundai Motor Co. revealed that 97 workers have accessed Internet gambling sites at work, leading the company to discipline them for improper use of company computers, corporate officials said Sunday.

The audit was launched in April after the company received a whistle-blower's tip that some employees on production lines were betting online with office computers while they were on the job, company officials said.

Thirty-five workers at Hyundai's plant in Asan, about 100 kilometers southwest of Seoul, were disciplined for accessing gambling sites, and another 62 workers at Hyundai's main plant in Ulsan will soon be punished, officials said.

"While the fact of cyber gambling was uncovered by an internal tip-off, the number of employees who gamble over the Internet at work appears to be higher (than reported figures)," a company official said on the condition of anonymity.

In particular, the audit found that 13 former and current union representatives were among the workers accused of accessing Internet gambling sites.

The audit comes as Hyundai Motor has been at loggerheads with its powerful union over its move to cut the number of its full-time union members under a new labor law that took effect last year.

Earlier this month, Hyundai Motor's Asan plant was forced to halt output for two days after unionized workers walked off the job after one of their colleagues committed suicide.

Police confirmed that the 49-year-old union representative, identified only by his surname Park, hanged himself in a bathroom of the plant, leaving a suicide note that blamed Hyundai's management for interrupting his duties as a union member.