A 38-year-old woman confessed to abetting the murder of her husband during a Tamil television reality show.
She surrendered before the police five months after the incident, which was initially treated as a case of suicide.
She is alleged of killing her husband with the help of her aide T Rajan on May 14 at their house in Marakadai.
D Sumathi was produced in a court in Tiruvarur district and remanded to judicial custody recently.
T Rajan also surrendered two days later and was remanded to judicial custody, police said.
The victim, 46-year-old S Dhanasekar, was a headmaster in a government school and his wife Sumathi was also a teacher in another government-aided school, both in Tiruvarur district.
S Kannadasan, brother of the victim, claimed that soon after his brother's death, Sumathi herself admitted to the crime to family members, "pricked" by conscience. Later, she confessed to the crime in the TV show a few weeks ago.
Police said murder charge has been framed against the two accused.