The arrest of former TMC MP K D Singh in a money laundering case has triggered a fresh verbal duel in the poll-bound West Bengal. The BJP has demanded questioning of the top brass of TMC in the case, while the Mamata-led has denied all association with Singh. Bengal BJP Vice President Jaiprakash Majumdar said that since Singh is a former TMC MP, the best thing would be to question the TMC leaders to bring out the truth. The TMC leadership, however, denied any association with Singh for the last few years. "He has not been associated with us for a long time. For the last few years, we have no relation with him. If he has committed any wrong then the law will take its course. We have nothing to say regarding it," TMC MP Sougata Roy said.