Prime Minister Atal Bihari Vajpayee on Tuesday described as 'forged' the document furnished by Chattisgarh Chief Minister Ajit Jogi and ordered a Central Bureau of Investigation probe into it.

"I am sure given the high constitutional office you hold, you will readily and fully cooperate with the CBI," Vajpayee said in a letter to Jogi.

Jogi had alleged that the operation, code-named 'Black Sea', had been launched by the IB special directorate, at the behest of the home affairs ministry, to target opposition leaders, including Congressmen like him, in the run-up to the election campaign in Congress-ruled states.

Vajpayee said, "I am informed by the Director of Intelligence Bureau that there is no 'Special Directorate' in the Intelligence Bureau and that it has not launched an operation code-named 'Black Sea' as mentioned in your letter."