'Operation Cocoon' which ended with the killing of forest brigand Veerappan and three others in the forests near Dharmapuri, was a meticulously planned action based on extraordinary intelligence, K Vijaykumar, chief of the Special Task Force, said on Tuesday.

Also read: Sandalwood smuggler Veerappan shot dead | The Veerappan Saga

"The ambulance in which Veerappan and his gang were caught was our's, driven by an STF man," he said. Last night's encounter was not a "flash in the pan but a joint operation meticulously carried out by both Karnataka and Tamil Nadu STF," Vijaykumar, an additional director general of police of Tamil Nadu, said.

Complementing Karnataka IG Jyothi Prakash Mirzi and other officials for their cooperation, Vijaykumar said prison officials in Tamil Nadu, Bangalore and Kollegal provided 'some vital intelligence' which played a role in the killing of the gang members. However, he refused to give details.

In addition to the intelligence on specific movements of Veerappan in Dharmapuri forest, a trap was planned to lure the gang out of the forest, Vijaykumar said. Veerappan and his associates fell for to the trap and walked into the STF hands.

Our planning and patience paid off, he said. Asked whether any DNA tests were carried out to confirm his identity, Vijaykumar said no such tests were conducted. STF had used the thumb rule to identify Veerappan, he said, adding that Veerappan had trimmed his moustache and was wearing a white dress instead of his usual green.

Kumar said that the task force had evolved a special strategy to bring Veerappan to the eastern area of the forest since he was in search of men and material. He also said there was a leadership tussle going on between Veerappan and gang member, Govindan.

Elaborating on the operation, Vijaykumar and Karnataka STF chief Jyothi Prakash Mirzi, who also addressed the press conference, said they had planned the operation two or three weeks ago.

"After the vehicle was surrounded, the STF twice ordered the gang members to surrender. But the gang opened fire, forcing the STF to retaliate. One grenade was thrown into the vehicle and the STF also started firing. The operation began at 10.50pm and ended at 11.10pm," he said.

On rumours claiming that the encounter was staged, he said, "I cannot react to that, you have every liberty to come to any conclusion."

"We believe the gangmen killed in the encounter were from Veerappan's core group, but there might have been some accomplices too," he said.