South Korean prosecutors are questioning Lotte Group's chairman in a corruption probe at the country's fifth-largest business group.

Shin Dong-bin told reporters outside the Seoul Central District Prosecutors' Office building on Tuesday that he regretted causing concern and will cooperate with the prosecutors.

Lotte Group, which operates South Korea's largest discount and department store chains, is a household name in South Korea.

The months-long investigation into allegations of slush funds, embezzlement and tax evasion at Lotte was halted temporarily after the group's vice chairman was found dead last month in a suspected suicide just hours before he was to face questioning.

Lotte withdraw an initial public offering plan for Hotel Lotte in June due to the probe.