Tripura Communist Party of India (Marxist) leader Jitendra Das, along with his two younger brothers and his nephew, has been sent to police remand in connection with his wife murder.
The four, who had been produced in an Agartala court on Saturday, had been earlier arrested in connection with the case after the 62-year-old Kalpana Das was found dead in her room.
Kalpana's body, which had been found with multiple cuts, was initially thought to have committed suicide.
"Evidence collected by the IO (investigating officer) and medical expert reveals that this is a case of homicide. The accused have tried to conceal something," Public Prosecutor Tapan Saha said.
The CPI (M) had dismissed Das from the party on Friday evening.