A police team led by Inspector General P. Vijayan did not reveal details about the investigation but says they have been able to track down all the accused.
They have made three arrests and are keeping a close tab on the prime accused and three others.
The actress was abducted on Friday night while she was on her way from Thrissur to Kochi.
She was dumped near a director-turned-actor's house, from where the police were informed and her driver Martin was arrested.
The victim told the police that Pulsar Sunil committed the crime at the behest of others.
Sunil reportedly told her that he had been hired to kidnap her and if she resisted, he would have to use force.
Sunil has been a driver in the film industry for actors and others for some years.
The actress lives in Kochi with her mother.
