The interrogation of a prosecutor with suspected links to a political meddling scandal involving former Prosecutor-General Yoon Seok-youl ended late Tuesday night after nearly 13 hours.

The Corruption Investigation Office for High-ranking Officials(CIO) began questioning Son Jun-sung at 10 a.m. on suspicions he ordered prosecutors to file complaints against pro-government figures ahead of last year's general elections. 

He is also suspected of conspiring with People Power Party(PPP) Rep. Kim Woong to lodge the defamation complaints.

It was the first summons of any suspect linked to the scandal since the CIO began its probe in September. It had requested an arrest warrant for Son last month but it was rejected on insufficient grounds. 

CIO prosecutors reportedly focused on what role Son might have played in the Telegram transfer complaints to Cho Sung-eun, an informant in the election-meddling scandal. The transfer was made under Son’s name, though he reportedly denied most of the allegations. 

Meanwhile, the CIO will likely summon lawmaker Kim Woong on Wednesday for questioning.