His brother Nishal, a Belgian citizen, also left the country on January 1, while his wife Ami, a US citizen, and business partner Mehul Choksi, the Indian promoter of Gitanjali jewellery chain, flew out on January 6, the officials said.
The agency issued a look out circular against all the four after registering the first FIR against them on January 31, according to officials.
A look out circular is issued by enforcement agencies to all exit and entry ports to inform them about the movement of an accused.
Nirav Modi is believed to be in Switzerland according to the Press Trust of India.
He was present in a group photo of Indian CEOs with Prime Minister Narendra Modi at Davos on the sidelines of the World Economic Forum on January 23, six days before state-run PNB sent its first complaint against him to the CBI, according to the officials.
The diamond merchant is an India citizen but his brother Nishal and wife Ami are not Indian nationals, the officials said.
Nirav Modi, a regular feature on the lists of rich and famous Indians since 2013, was charged by the CBI, along with wife, brother and business partner Mehul Choksi on January 31, for allegedly cheating the bank out of Rs 280 crore.