Mansa senior police chief Nanak Singh confirmed that the singers were summoned on different dates. The SSP added that police could not reveal the date when the singers would be questioned for security reasons.
Although Punjab Police cleared Mankirt in June, his name was once again included in the investigation.
Reports also claim that music director Nishan Singh and two Muktsar district residents have also been summoned for questioning.
Furthermore, last month, singers Dilpreet Dhillon and Afsana Khan were summoned by the National Investigation Agency (NIA) for questioning at its headquarters in New Delhi.