The prime minister is staying at the Grand Presidential Suite of the hotel on Mansingh Road in central Delhi. The suite, which houses a library, private workout area and a private pantry, has hosted many heads of state or government in the past.
The suite is guarded by Cameron's personal security guards. The hotel's security staff form the second layer of the prime minister's shield. Delhi Police are providing the third layer of security.
"We have deployed about 1,000 Delhi Police personnel, including commandos, anti-sabotage team and the dog squad, around the hotel to ensure fool proof security," said a senior security official.
Cameron, 43, the youngest British prime minister in almost 200 years, was accorded a ceremonial reception at the Rashtrapati Bhavan in the morning. He began his two-day visit to India from Bangalore.