First class judicial magistrate Mohmmed Omar held the MLA guilty under section 353 and sentenced him to one-year jail- term.
However, the court granted Mahto, who represents Baghmara constituency, bail to move the higher court.
The excise department filed the case against Dhullu Mahto on December 26, 2006 accusing him of snatching away his supporter Shahdeo Mahto from police custody when later was arrested in connection with illegal transaction of liquor.
Raj Bhallav Yadav would surrender before the court on February 18.
RJD suspended Yadav from the party on Sunday last. The party also served a show-cause notice to the MLA.
Yadav won from Nawada seat in the recent Assembly election.