"We don't know how much money has really gone abroad," Mr Modi said in the radio address "Mann ki Baat".
"Nobody, not this government, not you, not the previous government, knows exactly how much black money is stashed abroad," he said. "I don't want to get into the figures. Whether it is two rupees or five rupees or crores, I'm committed to getting that money back."
"I will not compromise anywhere. Please trust this Pradhan Sevak. The issue is an article of faith for me," he said. (We Are on Right Track on Black Money: PM)
"From what I understand and based on the information I have, I am telling you that we are (moving) in the right direction," he added in the 18-minute address.
The NDA government has come under fire over the BJP's pre-poll promise of bringing back black money parked in illegal accounts abroad within 100 days of coming to power. The Congress has claimed that the Prime Minister promised to bring back Rs 55,000 crore stashed abroad and almost every Indian will have Rs 15 lakh in his bank account. (Listen to the Speech)
But the government says it is bound by tax treaties that ban the disclosure of names at preliminary stages of inquiry. Eight names were revealed in court last week.
On Thursday, in an exclusive interview to NDTV, Justice MB Shah, who heads the special committee tasked by the Supreme Court to probe the black money issue, said the investigation will be completed by March 31, the deadline set by the court. (Read: Will Go Beyond 627 Names: First Interview by Black Money Probe Panel)
The Prime Minister had started his radio chats on October 3 with a 15-minute speech titled 'Mann ki Baat'. Future sessions, he had said, will be held on Sundays at 11 am on the All India Radio.