A prosecutor-turned-lawyer was summoned Friday to face questions over suspicions he illegally peddled his influence for his clients and evaded taxes in the process.

Hong Man-pyo appeared before the Seoul Central District Prosecutors' Office in southern Seoul as a suspect in the snowballing corruption scandal that is rocking the country's legal sector.

"I will fully cooperate with the investigation," he told reporters before entering the prosecutors' office. Still, the 56-year-old denied allegations he unlawfully contacted his former colleagues to advocate his clients.

Hong is suspected of peddling his influence for Jung Woon-ho, the chief of the South Korean cosmetics brand Nature Republic over his overseas gambling charges.

Before the businessmen was indicted in October, two separate investigations were launched on his gambling charges, but both ended without an indictment.

Last month, the Seoul High court handed down an eight-month jail term to Jung, reduced from the original one-year sentence meted out by a lower court.

The summons was made a few weeks after lawyer Choi You-jeong was formally arrested over allegations she took money from Jung in return for a promise to use her status as a former judge to advocate for him.

The prosecutor-turned-lawyer is also suspected of working for local business tycoons without filing a report, in violation of the attorneys-at-law act and dodging taxes in the process.

He partially admitted to the tax evasion charges, saying he could have made some mistakes because he has to work very long hours as a lawyer.

Hong was a prominent prosecutor until he stepped down from office in 2011, investigating major corruption cases that involved the country's former presidents. (Yonhap)