Mahachandra Singh was disqualified by legislative council Chairman Awadesh Narain Singh after hearing his case. Mahachandra Singh is one of the five rebel JD-U members in the council.
"Awadesh Narain Singh has disqualified Mahachandra Singh and likely to give his verdict on the fate of other rebel JD-U legislators on December 4 after hearing," the official said.
Mahachandra Singh joined the Hindustani Awam Morcha of former chief minister Jitan Ram Manjhi and contested the Bihar assembly polls as its candidate without resigning as member of the house.
Last month, the ruling JD-U petitioned the council chairman for the disqualification of its five rebel members under the anti-defection law. After that the council chairman had issued notice to all the five MLCs.
The other four rebel legislators are Narender Singh, Rakesh Kumar alias Samrat Choudhary, Shiv Prasanna Yadav and Manzar Alam.
JD-U spokesperson Neeraj Kumar said it was a clear case of defection as the party legislators had indulged in anti-party activities.