The finance director who played a key part in raising slush funds at an affiliate of Hyundai Motor has fled the country, according to the Korea Herald.

His absence is hindering the investigation of a lobbying scandal involving the nation's largest automaker, the prosecution told the paper.

The report said the man worked with Lee Ju-eun, chief executive officer of Hyundai's delivery service unit Glovis to amass 7 billion won of slush funds. He left for China on Friday on a business trip, right before a weekend raid on the offices of Kia Motors, an affiliate of Hyundai, the prosecution said. The date he was due to return has passed, prosecutors said.

The Korea Herald said the CEO of Glovis, who was officially arrested on Tuesday and charged with embezzling company funds, claims his subordinates created the slush funds. He has denied allegations that he received orders to create the cash pool from his superiors, refusing to implicate Hyundai Motor chairman Chung Mong-koo in the scandal.

The paper suggested the disappearance of the finance director may cause a glitch in the prosecution's probe similar to one in a 2002 case when an investigation into illegal political funding by Samsung came unstuck following the sudden departure overseas of one of its employees.

Rumours are circulating that the prosecution tried to search the offices of Chung and his son, Kia Motors President Chung Eui-sun over the weekend, the report noted.

The raids were part of a probe of slush funds believed to have been delivered to a lobbyist Kim Jae-rok who was arrested last Friday on charges of bribing government officials and arranging illegal bank loans for corporations.

Prosecutor Chae Dong-wook of the Supreme Public Prosecutors' Office neither confirmed nor denied to the Korea Herald reports that the raids took place.

The next company on the list to be probed by prosecutors is Hyundai Autonet, a producer of car accessories such as navigation systems and car stereo systems.

The prosecution will start summoning Hyundai Autonet officials next week, while "taking it slow" on probing other corporations involved with lobbyist Kim Jae-rok, prosecution sources told the paper.

Besides allegations of his connection to slush funds created at Hyundai Motor, lobbyist Kim Jae-rok is also accused of receiving 1.45 billion won from two banks in return for arranging loans for two shopping malls. "Kim Jae-rok claims that the money was a consultation commission, and that the loans were legitimately made," Prosecutor Chae said, according to the report.

But it is still possible to press criminal charges against him for taking bribes, Chae said.

The prosecution told the Korea Herald it interrogated Lee Jung-dae, vice executive of Hyundai Motor, on Wednesday and is continuing to analyse the material seized from last weekend's raid of Glovis which they will wrap up by the weekend.