New Delhi, Nov 3 (IANS): Sources in the National Investigation Agency (NIA) said on Thursday that it recently questioned two Punjabi singers in connection with the killing of popular Punjabi singer Sidhu Moosewala in May this year.

The NIA questioned Dalpreet Dhillo and Mankirat Aulak for hours at it's Delhi headquarters.

"Dhillo had alleged connection with jailed gangster Lawrence Bishnoi after the Bambiha Gang had threatened Moosewala," the sources said.

Both the singers were asked questions realted to Bambiha Gang and Lawrence Bishnoi. They were also asked about a few of their peojects. The sources said the two singers joined the investigation on seperate days.

The NIA had recently questioned pop singer Afsana Khan in connection with the case.

The Lawrence Bishnoi gang allegedly killed Moosewala to avenge the death of Vicky Middukhera. But before Moosewala was gunned down, a number of persons in the Punjabi pop industry were threatened, while a few were also attacked.

The sources said the NIA is trying to explore the tiffs between gangsters and the Punjabi pop industry.

The police have so far arrested over a dozen gangsters in connection with the murder of Moosewala. According to the sources, few more persons involved with the Punjabi pop industry are likely to be summoned for questioning in the coming days.