Naam Tamilar Katchi (NTK) candidate Karthika was arrested early on Tuesday, October 20, in connection with a road blockade during Tamil Nadu Chief Minister C. Joseph Vijay's election campaign roadshow in Dharapuram on October 4, according to India Today reporting carried by News89. Karthika had contested the recently concluded Dharapuram Assembly by-election, held on October 6, and was named in an FIR registered on the day of the protest.

The protest led to an altercation between NTK and TVK cadres after Karthika and her party workers entered the route of Vijay's roadshow, the report said. Karthika's friend Srinivas told India Today that police had also arrested her husband, alleging that officers climbed over the compound wall to take the couple into custody and that the family was not being given information. Those claims are the family's account, as reported; police have not publicly responded to them in the reports available.

Opposition leaders across parties condemned the arrest. NTK chief Seeman accused the TVK government of filing false cases to settle political scores, calling it, in his words, the 'despicable politics of the Thavega government' and warning that 'no power is permanent'. DMK president M.K. Stalin said the arrest over a case registered during the by-election campaign was 'strongly condemnable', and DMK MP Kanimozhi accused the government of trying to suppress opposition parties. The Times of India reported that Stalin also criticised the arrests of Karthika and five other NTK members.

On Wednesday, October 21, Tamil Nadu BJP president Nainar Nagenthran also condemned the arrest as political repression, according to IANS. He alleged that police entered Karthika's residence at about 5 a.m. and questioned why a pre-dawn arrest was necessary instead of a summons, also raising the legal restriction on arresting a woman between sunset and sunrise without prior judicial authorisation. The arrest has triggered a wider political storm in Tamil Nadu, with opposition parties accusing the ruling TVK government of using the police against its critics — an allegation the government had not answered in the reports available at the time of publication.