In a major development to the Narada sting operation case, the CBI team arrived on Saturday at SBI bank in Kolkata to collect evidence.

Reports suggested that the Calcutta High Court had on Friday ordered the CBI to conduct a preliminary probe into the Narada sting operation.

A Division Bench of acting Chief Justice Nishita Mhatre and Justice T Chakraborty had asked the CBI to complete its preliminary inquiry in 72 hours.

Meanwhile, reacting to the Calcutta High Court order, West Bengal Chief Minister Mamata Banerjee on Friday had said that her government will challenge the order in the Supreme Court.

"Will challenge before the Supreme Court against Calcutta HC order directing preliminary inquiry by the CBI on Narada sting operation," the chief minister had said.