Thousands rally in capital Seoul calling for president Park Geun-hye to resign over alleged leaked documents scandal.

Thousands of South Koreans have taken to the streets of the capital, Seoul, calling for President Park Geun-hye to step down over a leaked documents scandal.

The Saturday evening protest came after Park ordered 10 of her senior secretaries to resign over the scandal, which is likely to deepen the president’s lame-duck status ahead of next year’s election.

The increasingly unpopular president has been accused of letting her old friend, the daughter of a religious cult leader, interfere in important state affairs.

Holding candles and signs reading “Who’s the real president?” and “Park Geun-hye step down”, the protesters marched through downtown Seoul after holding a candlelight vigil near City Hall.

Police estimated that about 9,000 people turned out for the biggest anti-government demonstration in Seoul in months.

“Park has lost her authority as president and showed she doesn’t have the basic qualities to govern a country,” Jae-myung Lee, from the opposition Minjoo Party and the mayor of the city of Seongnam, told the protesters from a stage.

Park has been facing calls to reshuffle her office and cabinet after acknowledging on Tuesday that she provided longtime friend Choi Soon-sil with drafts of her speeches for editing.

Her televised apology sparked intense criticism about her mismanagement of national information and a heavy-handed leadership style that many see as lacking in transparency.

There’s also media speculation that Choi, who holds no government job, meddled in government decisions on personnel and policy and exploited her ties with Park to misappropriate funds from nonprofit organisations.

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Prosecutors on Saturday widened their investigation by searching the homes of presidential officials suspected of interacting with Choi and receiving their office files from the Blue House – the presidential office and residence.

Prosecutors had previously summoned some of Choi’s key associates and raided their homes and workplaces, as well as the offices of two nonprofit foundations Choi supposedly controlled.

The saga, triggered by weeks of media reports, has sent Park’s approval ratings to record lows, and the minority opposition Justice Party has called for her to resign.

Al Jazeera’s Harry Fawcett, reporting from Seoul, said the scandal has taken South Koreans by complete surprise.

“The sheer extent of this scandal is one they really haven’t come across before. Certainly there have been a number of scandals involving presidents in the past, often to do with corruption in terms of money. This one is to do with the influence apparently being wielded over President Park Geun-hye by a longtime friend and associate.”

Choi reportedly masterminded the creation of the two non-profits, which managed to gather about $70m in corporate donations over a short period of time, and is suspected of misappropriating some of the funds for personal use.

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Choi’s lawyer, Lee Gyeong-jae, said she was currently in Germany, but would return to South Korea if prosecutors summon her.

In an interview with a South Korean newspaper earlier in the week, Choi acknowledged receiving presidential documents in advance, but denied intervening in state affairs or pressuring companies into donating to the foundations.

Choi and Park reportedly became friends in the 1970s, when Choi’s late father, Choi Tae-min, a shadowy religious figure who was a Buddhist monk, cult leader and Christian pastor at different points in his life, emerged as Park’s mentor.