The CBI has no idea about the whereabouts of the diamantaire Nirav Modi, who is absconding in the Rs 14,500 crore Punjab National Bank fraud case, informed sources said on Monday against the backdrop of reports from London that he has sought asylum in Britain.They said the CBI had sent a request to Interpol to issue a Red Corner Notice (RCN) against Nirav Modi and his uncle Mehul Choksi of the Gitanjali Group. "CBI has no confirmation yet about Nirav Modi's whereabouts," an official added."When the agency gets any information about his whereabouts, it will take further action," the sources said.The CBI had filed three FIRs between January and March to probe the PNB fraud. Most of the accused are common to these cases. The fraud was committed during 2011-17 by illegally issuing Letters of Undertaking (LoUs) and Foreign Letters of Credit (FLCs).A LoU is a letter of undertaking issued by one bank to other banks, based on which foreign branches offer credit to buyers.The Financial Times said that Modi had sought political asylum in Britain.Nirav Modi left the country along with his family in the first week of January, weeks before the scam was reported to the CBI.His wife Ami, a US citizen, left on January 6 and uncle Choksi on January 4.The PNB has claimed in different complaints to the CBI that several LoUs were fraudulently issued by its officials in connivance with Modi and the other accused in the case causing huge losses to the bank.