The National Investigation Agency (NIA) on Thursday arrested former "encounter specialist" police officer Pradeep Sharma in Mumbai for his alleged involvement in the Antilia' bomb scare case and the murder of businessman Mansukh Hiran, an official said.

An NIA team had picked up Sharma from Lonavla near Mumbai late on Wednesday night, after which he was brought to the central agency's office in south Mumbai for questioning, he said.

"The NIA also conducted a raid at his residence located in J B Nagar in Mumbai's Andheri (west) around 6 am, and the operation continued for several hours. The officials recovered some incriminating documents from his house," the official said.

After questioning him for a few hours, the NIA placed him under arrest on Thursday, he said, adding that Sharma will be produced before a local court once a medical examination is conducted on him.

Around two months ago, the NIA had questioned Sharma at its office for two days after his name cropped up in the case.

Sharma is the fifth person from the police department to be arrested in the case by the NIA. This is the eighth over arrest in the case.

Earlier, the agency had arrested police officers Sachin Waze, Riyazuddin Kazi, Sunil Mane. After their arrest, they were dismissed from service. The agency had also arrested former police constable Vinayak Shinde in this connection along with cricket bookie Naresh Gor.

On June 11, the NIA held Santosh Shelar and Anand Jadhav from suburban Malad, saying that both of them were involved in the conspiracy to plant the explosives-laden SUV near industrialist Mukesh Ambani's residence.

The SUV was found abandoned near Ambani's south Mumbai residence Antilia' on February 25 this year. Thane-based businessman Mansukh Hiran, who had claimed that he was in possession of the vehicle, was found dead at a Mumbra creek on March 5.