Pakistani sufi singer Rahat Fateh Ali Khan was questioned on Friday by the Directorate of Revenue Intelligence officials for allegedly carrying $1.24 lakh (about Rs 60 lakh) of undeclared foreign currency.
DRI sources said the investigation against Rahat and four of his associates was nearing completion and a case under Foreign Exchange Management Act (FEMA) is likely to be filed.
Rahat was quizzed for about three hours today, the third time since his detention on February 13 at Indira Gandhi International Airport in New Delhi.
The DRI officials also interrogated two foreign exchange dealers in Mumbai on Friday in connection with the matter.
The 37-year-old singer is likely to be questioned again on Saturday.
Besides Rahat, his manager Maroof, owner of an event management company Chitresh Shrivastava, and two employees of Mumbai-based Foreign Exchange firm were detained and questioned at length about the source of the money.
Rahat was detained when he, along with his 16-member troupe, was on his way to Lahore via Dubai.
Soon after their detention, searches were conducted simultaneously on the premises of Eyeline Telefilm and Events in Mumbai, owned by Chitresh, elder brother of Bollywood singer Aadesh Shrivastava.
Sources privy to the investigations claimed that the sleuths found Rs 51 lakh in cash which was seized besides some documents.
As per norms, no one can carry beyond $5,000 in cash and $5,000 in other instruments. The person has to declare the amount if he is carrying more than this to the Customs Department.
Meanwhile, authorities here have extended singer's visa to 10 more days after its expiry on February 14, sources said.
Khan is rated as a one of the top playback singer of Hindi film industry who has several hit numbers to his credit.
He won the Filmfare Award for Best Male Playback Singer this year for Dil To Bachcha Hai Ji from the movie Ishqiya.