Bomb service personnel are examining the device, planted by some unidentified persons, DGP P Kamaraj told reporters. Two wires were found connected to the pipe-like device which was sealed at both the ends.
Congress activists staged a demonstration condemning the incident.
"The report of the bomb detection and disposal squad is awaited for follow up action," he said after visiting the residence of Narayanasamy, who is in Delhi.
A case has been registered under the Explosives Substances Act. Narayanasamy told PTI that his driver noticed the object under the car in the wee hours.
The Union Minister said it only showed that activities of anti-social elements are on the rise in the Union Territory. Congress activists staged a demonstration condemning the incident.