A trap was laid on a tip-off that Rajan's associate would arrive in Kandivali to hand over the weapons to his aide yesterday, said a crime branch officer.
A person with suspicious movement was intercepted and upon frisking, two-country made pistols and five live cartridges were found with him.
The accused identified as Shobhraj Yadav (43), a resident of suburban Bhandup, was subsequently arrested and the firearms seized, police said.