NEW DELHI: As the controversy over downgrading the Lookout Circular (LOC) from “detain” to “inform only” against Vijay Mallya erupted once again on Thursday, the Central Bureau of Investigation repeated its stand that there was no foul play.On a day when BJP leader Subramanian Swamy joined Congress to allege that the vigil against Mallya was lowered on a purpose, sources in the agency claimed that the “detain” order had been issued by mistake. “It had no legal basis as no non-bailable warrant, a requirement under law, had been issued against him (Mallya),” said a CBI source, justifying the decision to downgrade the alert advisory to “inform only” category on November 24, 2015.Asked why his passport was not impounded after registration of FIR in 2015, agency sources emphasised that according to a Supreme Court judgement, the passport of a person can only be impounded when he has been charge-sheeted or if a trial is pending against him.“It was CBI which, based on a sourced information, registered an FIR against him (Mallya) in the Rs 900 crore IDBI Bank case... But the investigation had not begun as the documents had not been collected. No bank had approached us with a complaint against him either,” a source said.Sources said CBI had no reason to suspect that with his large business interests, Mallya, a frequent traveller to London, could escape. They said Mallya joined the investigation sessions on December 9,10 and 12, 2015 upon his return from London. They also pointed out that Mallya who left for London on December 23, came back in February 2016.“An officer had inadvertently ticked the ‘detain’ box in the LOC form sent to immigration authorities on October 12, 2015 while we only wanted ‘information’ about his travel. The mistake was corrected in second LOC form on November 24, 2015,” said an officer.“A bank fraud probe takes time to ascertain if a person has defaulted on loans. Once it had been had established that Mallya had committed the crime, we moved swiftly and got his passport revoked, non-bailable warrants against him were secured and finally he was charge-sheeted,” said another officer.CBI said Mallya had cooperated with the probe and even provided documents sought by it.“He was cooperating with us and our investigation was in the initial stages. We had no reason to doubt that he will leave the country,” added the officer.