The main gate to Seoul Detention Center is seen in this photo taken on Jan. 20. Yonhap

Detained President Yoon Suk Yeol has been moved to a solitary cell at the Seoul Detention Center's general wing after he was placed under formal arrest over the weekend, a correctional official said Monday.

Yoon was transferred to the 12-square-meter cell at the detention center in Uiwang, south of Seoul, on Sunday after the Seoul Western District Court issued a warrant for his formal arrest, according to Shin Yong-hae, commissioner general of the Korea Correctional Service.

"(Yoon) was moved from a holding room for suspects to the general detention wing, and (I) received a report that he spent the night well," Shin told lawmakers during a session of the National Assembly's legislation and judiciary committee.

Yoon's cell, which is known to usually hold five or six people, is similar in size to those where past presidents have been detained, according to Shin.

The official told lawmakers that Yoon cooperated with official procedures for his detention, such as taking a mug shot and undergoing a physical exam, noting that a personal correctional officer has been designated for his safety.

Shin said his office is also cooperating with the police and the Presidential Security Service to ensure security amid concerns over Yoon's supporters possibly taking drastic action, such as attempting to free the detained president.

Meanwhile, Yoon's lawyers called on the state anti-corruption agency to immediately withdraw its decision the previous day to restrict the detained president from visitations.

"Restricting family visitations is not for the purpose of an investigation but merely an act of venting against the president," Yun Gap-geun, his lawyer, said in a statement. (Yonhap)