The killing of an Australian missionary in a remote village in eastern India in 1999 was premeditated and well-planned, India's top investigation agency said today.

According to Herald Sun, Lawyers representing the Central Bureau of Investigation, India's equivalent of the FBI, said the killing of Graham Staines and his two young sons in Orissa state was the result of a conspiracy hatched by the main suspect, Dara Singh, and a dozen other men.

Singh is charged with leading a mob that burnt alive Staines and his sons, Philip, 10, and Timothy, 8, on the night of January 22, 1999, as they slept in their jeep in Manoharpur, a remote tribal village about 230 kms north of Bhubaneshwar, the capital of Orissa.

"Dara Singh, the principal suspect in the case, and his associates hatched a conspiracy to kill Staines and executed the crime in a well-planned manner," SK Mund, the CBI's lawyer, told Judge Mahendranath Patnaik.

Singh, who began planning the murder in 1998, had told a witness he wanted to "teach the Christian missionary a lesson".

Two days before the murder, Singh asked two men to collect people to attack Staines.

Mund said a final shape to the attack was given when Singh met his associates hours before the killing.

"Singh divided his associates into three groups and asked them to launch the attack on the missionary's vehicle," Mund said.

The CBI has charged 14 people in connection with the killings.

The defendants have denied the allegations. If convicted, they could face death by hanging.