Ambani security scare: Param Bir Singh appears before NIA; Shiv Sena hits out at Centre The former Mumbai top cop reached the National Investigation Agency's (NIA) office in Maharashtra capital in a car around 9.30 am, an official said. Share Via Email | A+A A- By PTI MUMBAI: Former Mumbai police commissioner Param Bir Singh appeared before the NIA here on Wednesday to record his statement in connection with the case of an explosives-laden SUV found near industrialist Mukesh Ambani's residence, an official said. Singh reached the National Investigation Agency's (NIA) office in south Mumbai in a car around 9.30 am, he said.