A Seoul court on Thursday refused to allow special prosecutors to search the presidential office, casting a cloud over an ongoing corruption probe of President Park Geun-hye and her associates.

The special counsel filed the lawsuit with the Seoul Administrative Court last Friday after its attempt to enter the presidential office Cheong Wa Dae to collect evidence was halted by her aides earlier this month for security reasons.

Independent Counsel Park Young-soo sought to suspend and nullify the presidential aides' rejection. But after an hour-long hearing Wednesday, the court dismissed the case, concluding that the independent counsel is not qualified to file such a request.

The decision can't be appealed, effectively precluding the prosecutors' search of the presidential office.

The investigation team's spokesman Lee Kyu-chul earlier said a search of Cheong Wa Dae will become impossible if the suit is turned down by the court.

Under the country's law, military facilities and other areas that handle confidential information cannot be searched without approval from the person in charge of the location. The law, however, prohibits the person from refusing to grant such consent unless it infringes upon key national interests.

The probe team said it will clarify its stance during a regular press briefing on Friday afternoon.

A presidential aide welcomed the court's decision.

"It is a fair decision in line with the law," the aide told Yonhap News Agency over the phone. "The court made a stern judgment with regards to what special prosecutors excessively pushed for, taking advantage of the public sentiment (against the impeached president)."

On the same day, the special prosecutors asked Acting President and Prime Minister Hwang Kyo-ahn to extend their investigation by one month. The current deadline is Feb. 28 and an extension can only be granted once. 

An aide to Hwang refused to give a detailed answer, tersely saying the acting president will review the issue.

During a parliamentary interpellation session last Friday, Hwang called on special prosecutors to "do their best" until the end of their probe period rather than hastily calling for an extension. (Yonhap)