South Korea's acting leader Hwang Kyo-ahn has refused to extend a probe by special prosecutors into a huge scandal involving impeached President Park Geun-hye, drawing the ire of the country's opposition parties.

The corruption controversy erupted late last year over accusations that Park colluded with a friend, Choi Soon-sil, to pressure big businesses to donate to two foundations set up to back the president's policy initiatives.

Hwang's spokesman Hong Kwon-heui said during a televised briefing on Monday that the probe had served its purpose and it was in the country's best interests for the investigation to conclude as scheduled on Tuesday.

"After much deliberation, the acting president has decided that it would be best for the country's stability to not extend the special investigation and for the prosecutors to take over," Hong said.

The scandal has led to weekly rival protests by tens of thousands of South Koreans, with some supporting Park and others calling for the ouster of the country's first democratically elected leader.

IN PICTURES: Seoul impeachment protests

Al Jazeera's Harry Fawcett, reporting from the capital, Seoul, said Hwang's decision had angered opposition parties, with one calling it an "example of tyranny". 

"There was a meeting of four main opposition parties and at least three of them now want to impeach the acting president," he said. 

The special prosecutor's team had sought to question Park but is now unlikely to have time.

In a statement, it said the decision was "regrettable" but vowed to "thoroughly wrap up the case" and cooperate with the state prosecutors who will retake control over the investigation.

"The prosecutors are disappointed as during the 70-day investigation they have not been able to examine the full scope of the scandal and that they have been denied to interview the president as well," Fawcett said.

Park, 65, was impeached by parliament in December and has been stripped of her powers until the Constitutional Court decides whether to remove her from office.

Should the Constitutional Court uphold parliament's impeachment of Park, South Korea would hold an election within 60 days of the ruling.

Park cannot be prosecuted while she remains president.


Source: Al Jazeera and news agencies