Sharpening his attack against CBI, senior BJP leader Dilip Ghosh on Monday wondered what action the central investigating agency has taken in the post-poll violence cases in which around 60 BJP workers were killed in West Bengal after the state assembly poll last year.

His comment came a day after he had stirred a hornet's nest by saying that some CBI officers are hand in gloves with the ruling TMC in the state.

"It (CBI) has not performed its duty properly. What steps has it taken in the post-poll violence case they are investigating? Around 60 BJP workers were killed in post-poll violence in Bengal. But nothing has moved so far, the investigation is going on for months," the BJP national vice-president told reporters.

The central investigating agency is investigating the post-poll violence cases in West Bengal as per directions of the Calcutta High Court.

When asked to comment on the controversy he has courted by saying that some CBI officers have a "setting" with the TMC leadership, Ghosh said he is "not bothered" about what others think about his remarks.

"I have full faith in the Enforcement Directorate and I am confident it will bring out the truth. We(BJP) also had trust in the premier investigating agency (CBI). But we did not get justice. I stick to my comments on CBI. When I was the state party president, we had marched to the CBI office against its inaction," he said.

On Sunday, Ghosh had said certain CBI officers had a "setting" with the Trinamul Congress and because of this the Finance Ministry had sent ED to probe the corruption cases in West Bengal and speed up investigations.

The CBI had last week arrested TMC Birbhum district president Anubrata Mondal from Bolpur area of the state on August 11 for allegedly not cooperating in its probe into the cattle smuggling case. Partha Chatterjee, the now suspended senior TMC leader, and his aide Arpita Mukherjee were arrested on July 23 by the ED in connection with the shool recruitment scam.

The BJP state leadership has declined to comment on his remarks.

Reacting to Ghosh's remark, senior TMC leader Santanu Sen said the BJP leader himself has questioned the impartiality of CBI, which opposition parties too have been raising for the last few years.

"We have long said that ED and CBI are the frontal organizations of BJP. We have serious doubts about the functioning of the central agencies. Now Dilip Ghosh, a BJP leader, is also questioning the impartiality of the central agency," he said.