The court has also directed the CBI to take possession of all material and devices related to the sting operation within 24 hours.
"There is no other investigating agency besides the CBI which is independent and therefore I direct the CBi to conduct a preliminary inquiry without any delay", she said.
In its decision on Friday, the high court's bench comprising acting Chief Justice Nishita Mhatre and Justice T Chakraborti noted that the Central Forensic Science Laboratory report made it clear that the tapes had not been tampered with.
Chief Minister and Trinamool chief Mamata Banerjee had called the secretly-recorded video tapes a political conspiracy against her. The sting operation carried out by Narada news and led by its CEO Mathew Samuel, caught 11 Trinamool leaders, including 6 MPs, MLAs, and three top state ministers, besides a senior IPS official, accepting bribes from a non-existent company.
"We welcome the High Court verdict to conduct CBI inquiry on the #NaradaString". But since the state investigating agency also could make little progress in the probe, Arkadeb moved the high court again seeking a CBI investigation.
The ruling party Trinamool Congress had dismissed the authenticity of tapes by calling it "doctored".More news: Court rules Japanese gov't, TEPCO liable for Fukushima disaster
Meanwhile, reacting to the HC's order, Chief Minister Mamata Banerjee said that her government will approach the Supreme Court against the HC's order.
Banerjee also claimed those seen in the video footage had only taken donations.
Terming the state police a "puppet", the bench said society at large demands proper investigation on the issue.
"We will have to fight this politically and legally".
However, in August, the Calcutta High Court ordered an interim stay on the police probe while hearing the three PILs.