Indian health minister Anbumani Ramadoss has been charged with criminal conspiracy in connection with a murder case in southern Tamil Nadu state.
Mr Ramadoss says the charges are false
Mr Ramadoss, his father and four relatives are accused by a candidate of the ruling AIADMK party of involvement in the killing of an AIADMK worker.
Anbumani Ramadoss denies the charges, calling them politically motivated.
State assembly elections were held in Tamil Nadu on 8 May. Results are due to be announced on 11 May.
Members of the PMK party, founded by Mr Ramadoss's father, are blamed for hacking the AIADMK worker to death on the night of 8 May.
It is alleged that the Ramadosses and their relatives incited their party workers to carry out the attack in their native town of Thindivanam, 120km (75 miles) from Madras (Chennai).
The AIADMK candidate in the town, state education minister CV Shanmugham, says the attack was aimed at him, but he escaped.
As well as the man killed, many other AIADMK workers were injured, Mr Shanmugham said.
Anbumani Ramadoss accused the current state government of "foisting cases on false charges in a vindictive manner" against him and his family members.
His father, Dr S Ramadoss, said: "Fearing defeat in the assembly polls, Tamil Nadu Chief Minister Jayalalithaa is trying to create law and order problems in the state."
Opposition leaders allied with the PMK say they will meet the state's governor to complain about the police action against Mr Ramadoss and his family members.