Former Prime Minister Lee Wan-koo and South Gyeongsang Province Gov. Hong Joon-pyo are to be indicted without detention on charges of violating the Political Fund Act, prosecutors said Thursday, a decision that the opposition bloc viewed as “too lenient.”

The Seoul Central District Prosecutors’ Office was set to indict Hong and Lee for illegally receiving political funds, making them the first two political bigwigs to be prosecuted in connection with the high-profile bribery scandal involving President Park Geun-hye’s top aides.

The prosecutors, however, reportedly decided not to detain the accused despite circumstantial indications that Lee and Hong allegedly attempted to sway the investigation in their favor by pressuring witnesses not to make statements against them during the questioning.

The indictment came 38 days after prosecutors launched the investigation into the allegations that eight senior officials from the Park administration accepted illicit political donations from deceased business tycoon Sung Woan-jong.

Lee and Hong flatly denied the accusations during their questionings.

“We secured enough credible testimonies and circumstantial evidence to press charges against Lee and Hong by questioning Sung’s aides,” the prosecutors said, adding that their statements were specific and consistent.

The main opposition New Political Alliance for Democracy, meanwhile, took a swipe at the prosecution for taking a soft line on the accused.

“The prosecution’s decision not to detain them is obviously in favor of the ruling party,” said NPAD floor leader Rep. Lee Jong-kul, reiterating his calls for a thorough probe into the six other politicians listed on Sung’s memo.

The former premier Lee, who stepped down from the post on April 27, is suspected of receiving 30 million won ($27,000) from Sung in April 2013. Sung allegedly offered 100 million won to Gov. Hong in June 2011, when the four-term lawmaker ran for chief of the Grand National Party, the precursor to the ruling Saenuri Party.

By Ock Hyun-ju (laeticia.ock@heraldcorp.com)