NEW DELHI: A Blue Corner notice was issued on Wednesday against diamond jeweller Nirav Modi and his uncle Mehul Choksi of Gitanjali Group in connection with the Rs 12,600-crore Punjab National Bank (PNB) fraud case, an official said.An Income Tax department official said the Blue Corner notice — to locate, identify or obtain information on a person of interest in a criminal investigation — was issued by the Bureau of Immigration against the two which will be valid for a year starting February 22 at all ports of embarkation.The IT official also said that it has attached four more properties of the Nirav Modi group which include his farm house in Alibaug of Maharashtra worth Rs 13 crore and a 5.24MW solar power plant over 135 acres of land in the same state’s Ahmednagar worth Rs 70 crore, as per the books.The official also revealed that they have attached 34 more bank accounts and fixed deposits of the Gitanjali Group having a balance of Rs 1.45 crore.Meanwhile, the Central Bureau of Investigation (CBI) informed that it has written to Nirav Modi requesting him to join the investigation.”In reply to the CBI’s mail, the diamond jeweller showing helplessness said that he can’t join the probe as he has some pending business abroad.”The agency again wrote to him to immediately approach the high commission of the country where he is currently present and ensure his return as soon as possible.”He has been given time to join investigation till next week,” he said.The CBI official said that Nirav Modi has not shared anything with regard to his current location with the investigating agency.Modi has been accused, along with Choksi, of defrauding the PNB of Rs 12,600 crore, with Rs 1,300 being added to the fraud kitty on Monday night.Earlier, the amount stated to have been defrauded by Modi and Choksi companies stood at Rs 11,300 crore.The CBI had filed the first FIR in the scam on February 14 against Nirav Modi, his wife Ami, brother Nishal, uncle Choksi and his firms Diamond R US, Solar Exports and Stellar Diamond. The agency stated that the fraud involved an amount of around Rs 6,400 crore.Nirav Modi, his family and Choksi left the country in early January.The CBI filed a second FIR on February 15 for Rs 4,886.72-crore fraud against Choksi’s Gitanjali Group.To date, 12 persons have been arrested by the CBI in connection with the case. The Enforcement Directorate has claimed to have attached properties worth Rs 6,000 crore.