Former South Korean president Yoon Suk-yeol returned to a solitary jail cell on Thursday after a court approved a warrant sought by prosecutors investigating his attempt to impose martial law last year.

The Seoul Central District Court's decision bolstered the special counsel investigation into allegations that Yoon's move in December represented obstruction of justice and abuse of power.

The court said it granted the request because of concerns Yoon could seek to destroy evidence, returning him to confinement at the Seoul Detention Center where he spent 52 days earlier in the year before being released four months ago on technical grounds.

After his release, he moved back with his wife and his 11 dogs and cats to their 164-square-metre apartment in an upscale district of Seoul.

Yoon will now be housed in a 10 square-metre solitary cell and sleep on a foldable mattress on the floor without an air conditioner, an official at the detention centre and media reports said.

With a heat wave gripping the country, Yoon will have to rely on a small electric fan that switches off at night, Park Jie-won, an opposition lawmaker who had been incarcerated there, said.

The detention facility served a breakfast of steamed potatoes and mini cheese breads for inmates on Thursday, another official said.

The conservative politician faces criminal charges of insurrection over his martial law decree, which could carry a sentence of life in prison or death.

Hours after he ended up in jail, the court held a hearing on Thursday morning for his insurrection trial, but Yoon did not attend.

His lawyers told the court that he was unable to go to the hearing due to health issues, the Yonhap News Agency reported.

The Constitutional Court ousted Yoon as president in April, upholding parliament's impeachment for the martial law bid, which shocked South Koreans and triggered months of political turmoil.

The special prosecution team launched its investigation after new leader Lee Jae Myung was elected in June, and it has been looking into additional charges against Yoon.

The special counsel team is now expected to speed up its probe into allegations, including whether Yoon hurt South Korea's interests by intentionally inflaming tensions with North Korea.

The team plans to question Yoon on Friday, informing his wife and lawyers about his detention via letters, Park Ji-young, a deputy to the special counsel, told reporters on Thursday. (Reuters)