The prosecution Wednesday requested an arrest warrant for former National Police Agency Commissioner-General Kang Hee-rak for receiving kickbacks from a contractor in exchange for influence-peddling.

The investigators summoned former Korea Coast Guard head Lee Gil-bum on similar suspicions which allegedly involve several high-ranking police officials and politicians.

According to officials at the Seoul Central Prosecutors’ Office, Kang received 110 million won ($89,800) from Yu Sang-bong, a broker who demanded operational rights of makeshift cafeterias at construction sites. Those canteens, dubbed “hamba,” are known to be quite a profitable business. Kang is also suspected of making promotions at Yu’s request.

Investigators also found that Kang tried to conceal the case by asking Yu to flee abroad with 40 million won in August, just two months before Yu was arrested.

Prosecutors said Kang admitted to many of the allegations during questioning Tuesday.

They have also found that Yu operated several room salons in southern Seoul about 10 years ago where high-ranking officials were regulars. They are investigating whether people who have frequented the place have given favors to Yu, too.

The “hamba” scandal is now snowballing into one of the most sensational yet for the Lee Myung-bak government as Yu is alleged to have provided financial favors to a high-ranking official at the presidential office, a resort CEO, and three opposition and ruling party lawmakers.

Alarmed by the irregularities of the former chief, the NPA held an internal investigation and found incumbent deputy assistant commissioners and senior superintendents to have met Yu through Kang. They have reportedly admitted to having been asked favors of a kind in exchange for a large sum of money, but denied having taken it.

By Bae Ji-sook (baejisook@heraldcorp.com)