Former Coal Secretary P C Parakh, booked for allegedly abusing his official position to grant a coal block to Hindalco, today accused the CBI of being "unprofessional and under-equipped".

Parakh also said that his book "Crusader or Conspirator? Coalgate and other Truths", released recently, was all about "deterioration" of political and bureaucratic system in the country.

"My book is about the slow deterioration of our political and civil service system. I have seen this deterioration in my own service. I have seen how brazenly the political leadership indulges in and promotes corruption," Parakh said during the formal launch of the book here.

In the book, Parakh has been critical of CBI's action, especially of its Director Ranjit Sinha, for registering a case against him.

He also questioned the decision of the agency chief in not naming Prime Minister Manmohan Singh as an accused as the Coal Ministry was under Singh's charge directly when Talabira-II coal block in Odhisa was given to Hindalco.

CBI had last year registered a case against Parakh, Kumar Mangalam Birla, besides unnamed officials of Hindalco and the Coal Ministry in connection with the allocation of the coal block.

Taking a dig at CBI, Parakh said, "The investigating agency is unprofessional and under-equipped."

Quoting a Hong Kong-based consultancy report, Parakh said the Indian civil servant was rated as "the worst in Asia".

The book was released by Justice MJ Rao, former Judge of the Supreme Court and Chairman of Law Commission.