The widow and successor of the Unification Church founder Sun Myung Moon was arrested ​on Tuesday on charges of providing illegal political funds and bribing the wife of Yoon Suk Yeol, who was impeached and ousted as president of South Korea.

Han Hak-ja, 82, ​was being held in a jail south of Seoul after a court in the capital city issued a warrant for her arrest​ early Tuesday​. The court expressed concern that if she remained free she could try to destroy criminal evidence against her.

Ms. Han, known as “​True ​Mother​” among her followers​ in South Korea and abroad, has been leading the Unification Church since ​the Rev. Moon died in 2012 at age 92. She and her church​ have not drawn much public attention in South Korea, a country with no shortage of politically influential or scandalous religious leaders.​

But Ms. Han and ​the Unification Church suddenly made headlines this year in connection with criminal investigations targeting Mr. Yoon’s wife, Kim Keon Hee​.

Mr. Yoon plunged South Korea into months of political turmoil when he declared martial law last December as a move against his domestic enemies. He was expelled from office in April ​after his impeachment by the opposition-controlled National Assembly and is now on trial on insurrection charges.

Last month, ​Ms. Kim was arrested on charges, including accepting bribes. She is accused of accepting a diamond necklace and two Chanel bags from a senior official of the Unification Church after Mr. Yoon’s election​ in 2022.​ ​The official, who has since left the church, was also ​arrested, as was a self-proclaimed religious guru accused of working as an intermediary between him and Ms. Kim.