SEOUL, Feb. 20 (Xinhua) -- South Korean Prime Minister Hwang Kyo-ahn has yet to respond to the calls by special prosecutors to extend their investigation into a corruption scandal that led to the impeachment of President Park Geun-hye.

Lee Kyu-chul, spokesman of the independent counsel team which kicked off their investigation on Dec. 21, told a press briefing Monday that it had yet to get a response from Prime Minister Hwang who is serving as an acting president following President Park's impeachment in early December.

Under a special law, the independent investigation is scheduled to end this month. With Hwang's acceptance, the probe can be extended for up to 30 days.

In the absence of the interim president's response, the special prosecutors officially called for the extension once again in an apparent part of efforts to pressure Hwang into making a rapid decision on it.

The independent counsel team sent a letter to Hwang last Thursday to ask for the extension, but the caretaker leader has not replied yet though only eight days are left for the termination of the investigation.

The spokesman said that if Hwang gives a reply as rapidly as possible, it will help conduct an effective probe for the rest of the days allowed.

Hwang is widely forecast to refuse the prolonged probe as he is one of closest aides to the impeached president. The ruling Liberty Korea Party adopted the rejection on the lengthened one as its party line earlier in the day.

The main opposition Minjoo Party had submitted the revision of the law to the parliamentary judiciary committee to enable the special prosecutors to look into the influence-peddling scandal for 50 more days.