Terrorists who battled Indian commandos for 60-hours last week relied on cocaine and other stimulants to stay awake for the duration of the fight.
Officials said drug paraphernalia, including syringes, was recovered from the scene of the attacks, which killed almost 200 people.
The heavily built men, who had undergone training at a special marine camp established by the Lashkar-e-Taibat (LeT) terrorist group in Pakistan, had also used steroids to build a tougher physique.
"We found injections containing traces of cocaine and LSD left behind by the terrorists and later found drugs in their blood," said one official.
"There was also evidence of steroids, which isn't uncommon in terrorists.
"These men were all toned, suggesting they had been doing some heavy training for the attacks. This explains why they managed to battle the commandos for over 50 hours with no food or sleep."
One terrorist used the drugs to keep on fighting despite suffering a life-threatening injury.
Drugs are commonly used in India by workers in jobs where a lack of sleep is demanded, such as truck drivers and security guards.
The 10 men who attacked prominent Mumbai landmarks were able to hold off hundreds of India's best trained special forces by mounting sophisticated ambushes, maintaining a constant, steady rate of return fire and a superior knowledge of the layout of the buildings seized.
The gunman captured during the attacks on Mumbai has told police he underwent months of commando-style training in an Islamist militant camp in Pakistan.
The training was organised by the LeT and conducted by a former member of the Pakistani army, a police officer close to the interrogation said.
"They underwent training in several phases, which included training in handling weapons, bomb making, survival strategies, survival in a marine environment and even dietary habits," a senior officer said.
By Damien McElroy in Mumbai
Last Updated: 12:54PM GMT 02 Dec 2008