PCC required for US Visitor Visa? Help?

[Mynewportapt]

Hi - My in-laws are planning to visit US for tourism and stay with us. They recently applied for their passport in tatkal scheme and during that process, Passport office employee told them that they need to obtain PCC (Police Clearance Certificate) - basically a stamp in the passport by passport office.

I tried searching on VFS website as well as Immihelp but couldn't find exact reference of why PCC required for tourist visa. Any help would be greatly appreciated.

[peace999]

There is no such requirement for a visitor visa.

Have they received their passports?
Passport office employee would not know about visitor visa requirements,