He was arrested late on Wednesday evening from a village under Amba police station area in Aurangabad district by a joint excise and police team.
Ram, who was MLA from Kutumba assembly constituency in Aurangabad district, was seen purportedly consuming alcohol and cursing the chief minister for implementing prohibition in the state. He was quoted as saying that "nobody will follow him (Nitish Kumar) wherever he will go."
"Ram has been arrested on the basis of the video in which he was seen consuming beer. It has also been shown on various TV channels and published in newspapers," Assistant Excise Commissioner O P Mandal told PTI.
Mandal said that Ram has been booked for violating the provisions of the Bihar Excise (Amendment) Act 2016. The video, which went viral, was also shown on various TV channels on Wednesday.
Following his arrest on the basis of the purported video, the JD-U on Thursday suspended him from the party.
The former MLA was the organising secretary of the party's state unit and its organising in-charge of Aurangabad district.
"We have suspended ex-MLA Lalan Ram from the party with immediate effect for his involvement in such activity which is against the state government's prohibition policy," state unit president Bashishtha Narayan Singh told PTI.
Singh said that Ram has also been relinquished of all party posts.
Earlier, JD-U Member of Legislative Council Manorama Devi had been jailed after liquor was recovered from her residence in Gaya. A first information report was also lodged against Narkatiaganj's Congress MLA Vinay Verma after he was shown with a promise to offer liquor to his guests in a video.