The Delhi Police on Monday apprehended two men who were allegedly involved in robbing a delivery agent and one of his associates of Rs 2 lakh at gunpoint inside the Pragati Maidan tunnel, officials said.
The development comes two days after the incident that took place on Saturday.
In a statement issued late in the evening, Delhi Police's Public Relations Officer (PRO) Suman Nalwa said two men were apprehended, the remaining suspects have been identified and raids are being conducted to arrest them.
Footage obtained from more than 350 CCTV cameras was scanned in the last 48 hours to identify the four motorcycle-borne men who allegedly robbed the delivery agent and his associate, the police said.
The staff of the delivery agent's company, his employer and associates have also been questioned, they added.
The delivery agent of Omiya Enterprises, Chandni Chowk and his associate were robbed of Rs 2 lakh when they were going towards Gurugram in a taxi to deliver the money, the police said.
"We have scanned the footage obtained from more than 350 CCTV cameras installed along the route towards the Pragati Maidan tunnel and the way ahead to ascertain the route taken by the assailants after carrying out the robbery.
"Though CCTV cameras captured the incident clearly, we could not see the faces of the motorcycle-borne robbers as they were wearing helmets," a senior police officer said.
The police suspect the involvement of more than four people in the robbery and said they have got clues regarding the modus operandi of the accused.
"We suspect six people were involved in the robbery. Though the involvement of the four accused has been established through the CCTV footage, the probe so far has revealed that the robbery was executed on the directions of someone else, who could be an insider and knew that the victim was carrying a huge amount of cash on that particular day," he said.
A 22-second video of the incident received by the police shows that the four men were following the taxi on two motorcycles and intercepted it inside the tunnel as other vehicles passed by.
As the taxi stopped, the two men riding pillion got off the motorcycles. While one of them went towards the driver's seat, the other went towards the rear door of the car, both apparently whipping out their pistols. All four were wearing helmets.
The footage then showed that the car gates opened and the man at the rear door was handed over a black handbag, apparently containing the money. The two men then quickly hopped onto the waiting motorcycles and fled with their accomplices.
Officials said the incident was caught in one of the CCTV cameras installed inside the 1.5-km tunnel that connects New Delhi with Sarai Kale Khan and Noida.
A case has been registered under Sections 397 (robbery, or dacoity, with attempt to cause death or grievous hurt) and 34 (common intention) of the Indian Penal Code, the police said.
