Kolkata, Oct 13 (IANS): Congress leader Somen Mitra on Thursday expressed doubts about the motive behind Mukul Roy's resignation from the Trinamool Congress and claimed there could be "a secret understanding" between him and the top party leadership to hide "wrongdoings" of some leaders.

Mitra, who quit the Trinamool to rejoin the Congress in early 2014 and was also its state unit chief, claimed that Roy had no alternative other than returning to Trinamool in future.

"I have a suspicion from the outset about whether this is a real separation between him and the party. I am skeptic because everything is dependent on internal understanding. I think there is an understanding between him, the state government and the party supremo. May be, both sides have some interest," the veteran leader told local news channel ABP Ananda.

"Mukul Roy knows many secrets about the party as he was there since the party's inception. Also according to some of their leaders he has built up a good rapport with some BJP leaders. Taking help of his relationship with the BJP leadership, there may be an attempt to conceal the misdemeanour of some of their (Trinamool) leaders here," he alleged.

He claimed that once the purpose was fulfilled, there could be a possibility of a reunion between Roy and the Trinamool.