Stalin is the son of Tamil Nadu Chief Minister M Karunanidhi and the front-runner to succeed him as head of the government.
The opposition All India Anna Dravida Munnetra Kazhagam, which released the video showing Stalin distributing money, has called it a violation of the poll code.
Both the DMK and AIADMK are engaged in a bitter fight over the Thirumangalam constituency near Madurai where by-elections are to be held on January 9.
The video showed Stalin distributing money, but the DMK claimed the recording was not recent nor from Thirumangalam but from a party function.