Chung Yoo-ra is being represented by the same lawyers defending her mother, but her surprise appearance in court Wednesday prompted one of them to dismiss her testimony publicly as "tainted" by a possible deal with prosecutors.

One of the attorneys, Oh Tae-hee, said Thursday, "She can't be reached, perhaps because she blocked the phone numbers of her lawyers."

The daughter of ex-President Park Geun-hye's confidante Choi Soon-sil has broken contact with family lawyers after she gave damaging testimony in the trial of Samsung chief Lee Jae-yong on Wednesday.

Chung testified in Lee's bribery trial that her mother told her to "shut up" about billions of won in support from Samsung, flatly contradicting Choi's protestations of innocence.

Chung lives in a building owned by her mother in the swish Gangnam district. Her lawyers have even asked her estranged father, Chung Yoon-hoi, why she spilled the beans in court.

Choi sat expressionless in her own bribery and corruption trial on Thursday behind Lotte Group chairman Shin Dong-bin, who is also charged with bribing her and Park.

Her lawyer, Lee Kyung-jae, said, "She is very disappointed. It seems certain that some type of deal has been made with prosecutors. It is not normal for [Chung] to appear at the trial despite attempts by her lawyers to stop her."

Chung has made no public comments since appearing in court, so it remains unclear what caused the change of heart. Legal experts said she may be hoping for a lighter sentence if she cooperates with the prosecution.

Oh said Choi showed great interest in what her daughter said in court on Thursday. "Choi asked us to contact her daughter and verify whether she intends to continue making comments that could prove to be detrimental to her mother," he added.

She also said her daughter should be appointed an attorney by the state if her lawyers decide not to defend her. "Choi said her daughter is a disgrace for making such comments in court without consulting her lawyers, who are working until late into the night to defend them."

He quoted Choi as saying, "How dare she make comments that could hurt her mother, who faces 10 to 15 years in prison and stands to have all of her wealth confiscated."

He added the family lawyers are mulling whether to stop defending her.

