West Bengal BJP said that party would not stand behind or give cover to Mukul Roy any leader found guilty in the eyes but added that Roy's guilt remains to be proved.

Kolkata: As former Trinamool Congress leader Mukul Roy joined the BJP, its West Bengal state unit on Friday said the party would not stand behind or give cover to any leader found guilty in the eyes of the law but added that Roy's guilt remains to be proved.

The one time second-in-command of Trinamool, Roy's name figures in both the Saradha ponzi scam and Narada sting cases.

"Those who are found guilty will be punished. The party won't stand behind them or give them cover. Leaders of a lot of parties, including the CPM, have got involved", said West Bengal BJP chief Dilip Ghosh.

Regarding Roy, Ghosh said it was yet to be proved that he was guilty.

"It remains to be proved that he is involved. The state government has sent to jail some of our party leaders also by involving them in various cases. That doesn't mean they are involved", he said.

State Congress president Adhir Ranjan Chowdhury trained his guns on Trinamool supremo Mamata Banerjee, alleging she believed in the "use and throw" policy, and that Roy switched over to the BJP as he had no other option.

"Mukul Roy has been groomed in the Congress gharana (family). He has gone to the BJP because there was no other option before him.

"It is also a big question why Mukul Roy, who founded the Trinamool and was also its second in command at some point of time, had to leave the party.

"That's because the Trinamool supremo believes in the use and throw policy," he said.

Roy had been sidelined in the Trinamool in the months leading up to his resignation from the party. He was divested of all posts and responsibilities and ignored in crucial party matters. In an organisational reshuffle, Banerjee even abolished the Vice President's post he had been holding for over a year.

Late September, Roy announced his decision to quit the party and his Rajya Sabha membership.

He formally joined the BJP on Friday in New Delhi in the presence of its senior leaders.

The CPM led Left Front however, saw a covert nexus between Prime Minister Narendra Modi and Banerjee in the latest episode.

"Banerjee used him for all her dirty work, and has released him for the time being. And now, Modibhai has roped him to do the similar dirty jobs for him.

"It will be Roy's job to ensure the relations between Modibhai and didibhai (read Mamata who is populary called 'didi' or elder sister) are not spoiled," said LF legislature party leader Sujan Chakraborty.

But Chakraborty wondered whether Trinamool or Roy can survive in this way.

"If Trinamool or Roy think they can survive through such stratagems, I'll say that is a remote possibility."

Describing Roy as one of the main actors in the Saradha scam, Chakraborty said: "BJP has now proved that even such people can take shelter in its fold."