A Mumbai crime branch team, conducting a probe into a letter threatening actor Salman Khan and his father, reached neighbouring Pune city on Thursday and started interrogating Siddhesh Hiraman Kamble alias Mahakal, who was arrested in the case of murder of popular singer and Congress leader Sidhu Moose Wala, an official said.

The police will also question Kamble about who kept the threatening letter at a bench in Bandra area of Mumbai on Sunday, he said.