SEOUL — Former South Korean president Yoon Suk-yeol was indicted for abuse of power on Saturday over his ill-fated imposition of martial law last year, as investigators widened an insurrection probe.

Yoon plunged South Korea into a political crisis when he sought to subvert civilian rule on Dec 3, sending troops to parliament in a bid to prevent lawmakers voting down his martial law declaration.

He became the country's first sitting president to be taken into custody when he was detained in January after resisting arrest for weeks, using his Presidential Security Service to thwart investigators.

Yoon was released on procedural grounds in March, even as his trial on insurrection charges continued.

Earlier this month, he was detained again after an arrest warrant was issued over concerns he might destroy evidence in the case.

The prosecution "indicted former president Yoon Suk-yeol on charges including abuse of power and obstruction of special official duties", prosecutor Park Ji-young told reporters on Saturday.

Park said Yoon also did not follow the required procedure to declare martial law, including holding a meeting with all cabinet members of the government.

Yoon was also charged with "drafting and discarding a false document" that stated the prime minister and defense minister had endorsed martial law.

He has refused to attend questioning since he was detained, but appeared in court on Friday at a hearing to argue for his warrant to be canceled.

The former leader's legal team told reporters that Yoon defended himself for more than 30 minutes, and mentioned his "limited physical mobility and the challenges he was facing".

The court denied the request.

AGENCIES VIA XINHUA