Plaintiff Alisa Thomthitchong filed the lawsuit against Pemmika Veerachatraksit, 24, with the Central Juvenile and Family Court.

The court accepted the lawsuit and summoned the parties on May 22.

Pemmika, a fourth-year student at Chulalongkorn University (CU), recently attracted media attention when she accused Prakitpao's family of sending him to Srithanya mental hospital, despite being 'perfectly sane'.

On Monday, the court ruled that there was nothing wrong with Prakitpao being admitted to hospital because the 37-year-old was suffering from a mental disorder.

In her affidavit, Alisa accused Pemmika of having an affair with her husband since mid-2006.

The student has publicly spoken about her intimate relationship with Prakitpao, giving details that implied the pair were lovers.

She even said Prakitpao emitted blood when he ejaculated.

The affidavit said Pemmika's accusation against the family over his admission to hospital showed her desire to break up the marriage.

Alisa's lawyer Thonglang Paengsrilakorn said: "The Bt27-million compensation is not excessive considering what Pemmika has done to Alisa. There is irreparable damage caused to her honour and she has endured severe distress."

It is also claimed that the student publicly said Prakitpao condemned his wife for not taking proper care of him and only wanting money.

Thonglang added the family was also preparing to sue Pemmika through the civil courts.

Alisa has lodged a complaint with the police claiming Pemmika was responsible for a 10-digit figure in assets that were missing.

"If Pemmika comes out to plead guilty and shows her repentance, the family may forgive her," Thonglang said.

Galaya Rajanagarindra Institute director Dr Sirisak Thitidilokrat said Prakitpao had been buoyed by a visit from his children.

Before Monday's court ruling, the family had been banned from visiting.

Speaking for CU, Professor Kua Wongboonsin said the university would only launch a probe into Pemmika if the court found her guilty.