Guwahati: The chief minister's special vigilance cell (CMSVC) has summoned four proprietors of three advertising firms to appear before it on Friday for questioning in connection with a more than Rs 30-crore advertisement scam in the state information and public relations department.

According to a source, those summoned are Rajiv Bora and Anjana Bora of Brahmaputra Television Network, Dilip Kalita of Delta Publicity and Apurba Lahkar of Pradip Advertising.

These firms allegedly colluded with a section of officials of the directorate and siphoned off more than Rs 30 crore in 2015-16 during the tenure of the previous Congress government.

The cell had arrested the department's director, Ranjit Gogoi, on Tuesday for his alleged involvement in the scam.He was produced in the special court, Assam, here following expiry of his three-day police remand on Thursday. The court sent him to judicial custody for 14 days.