The special investigating team probing the Sankararaman murder case on Saturday detained jailed junior pontiff Vijayendra Saraswati's brother R Raghu and Kanchi mutt Manager Sundaresa Iyer under the Goondas Act.
The detention comes a day after the charge sheet was filed against Kanchi Shankaracharya Jayendra Saraswati and the junior seer in the case.
The SIT has already detained eight others - Kathiravan, Chinna, Ambikapathy, Mattu Basker, Meenakshisundaram, Anandkumar, Anil Kumar and K S Kumar - under the Act, taking the total number of detainees to ten, police said.
Of the 25 accused in the case, 23 have been arrested, while Jayendra Saraswathi, the main accused, was released on bail on January 10.
One of the accused, Ravi Subramaniam, has reportedly expressed his desire to become an approver and has become a prosecution witness.
The Goondas Act is invoked on those who have a series of cases against them, and who, in police parlance, are referred to as 'habitual offenders'.
Those detained under the Act cannot seek bail but can approach a review committee through an advocate for relief after three months of detention.