"Anant Singh, a bahubali legislator of JD-U from Mokamah, was arrested," Patna Senior Superintendent of Police Vikash Vaibhav told the media here.
Earlier, security forces led by Vaibhav entered the official bungalow of Anant Singh with a court order for search and questioned him and placed him under detention.
Police also arrested five people, considered close to Anant Singh, from his bungalow for interrogation in the case. "Police have recovered a magazine of Insas rifle and two bullet-proof jackets during the search," an officer said.
Under increasing pressure from the opposition and allies -- the Rashtriya Janata Dal and the Congress -- the JD-U government of Nitish Kumar directed the police to go ahead and take action against Anant Singh, known as "Chhote Sarkar" for his muscle and money power.
According to top police officials, Anant Singh was arrested in view of the hue and cry made by the opposition BJP to former chief minister Jitan Ram Manjhi, who is president of HAM, and JD-U's allies RJD chief Lalu Prasad.
Clash breaks out between JDU MLA Anant Singh and police officials outside police station in Patna pic.twitter.com/81XHtXMblA
Anant Singh's name came into the picture when four criminals arrested by Patna police in connection with a kidnapping and murder case revealed his involvement in it.
Clash breaks out between JDU MLA Anant Singh and police officials outside police station in Patna pic.twitter.com/81XHtXMblA— ANI (@ANI_news) June 24, 2015
Opposition Bharatiya Janata Party leaders have accused Nitish Kumar of transferring out Patna police chief Jitendra Rana -- who arrested the criminals -- to protect Anant Singh.
But Additional Director General of Police headquarters Sunil Kumar refuted it and said the transfer was a routine one along with seven other IPS officers.
Rana told media persons that the criminals allegedly responsible for the June 17 abduction of four men from Barh in Patna district -- one of those abducted was later murdered -- confessed to the police that they were acting on Anant Singh's orders.
Anant Singh has, however, denied any involvement in the case and his party has also backed him.
"It is a conspiracy by my rivals, who wanted to defame me and take political advantage ahead of upcoming Bihar assembly polls. It is nothing but purely politics by my rivals," Anant Singh said.
The legislator, who belongs to the powerful upper caste Bhumihar community and is considered close to Nitish Kumar, has dozens of criminal cases, including several for murder and kidnapping, registered against him.