Prosecutors questioned two employees of the Korea Customs Service last week, a prosecution official said Wednesday, as they began looking into allegations that local conglomerates gave kickbacks to former President Park Geun-hye and her friend in return for business favors.

A prosecution team looking into an influence-peddling scandal that led to Park's ouster grilled the employees in charge of duty-free shops on Monday, according to the official, who asked not to be named.

There have been allegations that the country's leading conglomerates, SK and Lotte, donated large sums of money to two nonprofit foundations controlled by Park's friend Choi Soon-sil in return for favors in winning licenses to run duty-free shops in Seoul.

Lotte was selected by the KCS to operate the shop, along with five other conglomerates, in December. SK was not included in the list.

Prosecutors attempted to delve into the allegations last year, raiding the headquarters of Lotte, SK and other government offices, but had stopped after an independent counsel team was launched to investigate the scandal in December.

The independent counsel team, however, wrapped up the probe late last month, leaving the issues implicating SK and Lotte unresolved.

Meanwhile, Lee Jae-yong, the de facto leader of the country's largest business group Samsung, was arrested and indicted on charges including bribery and embezzlement following the probe. (Yonhap)