Prosecutors are stepping up their investigations into corruption scandals involving politicians from both the ruling and opposition parties.

Political parties are keen to the development of the inquiries which coincide with the launch of a three-way race for the December presidential election and are expected to affect voter sentiment considerably.

Prosecution investigators on Thursday raided the home and office of Hong Sa-duk, a former lawmaker and close aide to Saenuri Party presidential nominee Park Geun-hye, in Seoul.

The former co-head of Park’s primary campaign team has been accused of taking 60 million won ($54,000) in illegal funds from a corporate owner, surnamed Jin, ahead of parliamentary elections in April.

The prosecutors also searched the offices of Jin’s company in Hapcheon, South Gyeongsang Province.

The National Election Commission on Monday filed a complaint with the prosecution to investigate allegations raised by the businessman’s former driver, who claimed that he delivered the money.

Hong denied the charges and left the party Tuesday in an effort to lessen any impact on candidate Park.

Prosecutors have already questioned the driver twice. A former staffer of Hong’s office who is said to have received the money was also questioned Thursday.

In a separate case, prosecutors stormed the homes and offices of opposition Democratic United Party lawmaker Choi Dong-ik and former lawmaker Jang Hyang-suk in Seoul and Busan later in the day.

Choi is suspected of having provided 70 million won to Jang in March and April, requesting her support for his bid to get the party’s nomination for the April parliamentary elections. The NEC referred the case to the prosecutors on Monday.

Choi was put on the No. 2 slot on the list of proportional representative candidates. Choi and Jang, both physically handicapped, are leading activists for the rights of disabled people.

Jang is also accused of having accepted 33 million won early this year from another lawmaker aspirant.

By Bae Hyun-jung (tellme@heraldcorp.com)