Amid the ongoing investigation of Sidhu Moose Wala`s killing, gangster Lawrence Bishnoi, who`s being interrogated in the case, was also questioned about the threat letter addressed to Bollywood actor Salman Khan and his father Salim Khan, police sources said.

Addressed to the actor had `L.B.` written at the end, thus pointing to the gangster`s initials. The threat letter was sent to him and his father Salim Khan on June 5.