Ran Vijay Singh, from the ruling Janata Dal-United (JD-U) nominee from Goh constituency, is in the Daudnagar jail over a murder case.
Singh is perhaps the only candidate from regional or national parties to contest the assembly elections from prison.
Goh in Aurangabad district, considered a Maoist stronghold, is one of 26 constituencies going to the polls in the last round of six-phased assembly elections Nov 20.
Singh has been in jail for over three years following a shootout at a polling booth in 2005.
"Nitish Kumar has appealed to the electorate to vote for the jailed legislator," said Ghalib Khan, a resident of Piroo village near Goh.
Surprisingly, many people say they are missing their legislator. Baijnath Prasad of Haspura said people have faced a number of problems because of their inability to access the jailed Singh. "He is a well-known muscle man who enjoys the support of the chief minister," he added.
The Congress, of course, thinks differently. Congress spokesperson Prem Chand Mishra told IANS that Nitish Kumar had exposed his true face by campaigning for a politician jailed for murder.
"This is the true picture of Nitish Kumar's tall claims of his so-called good governance and rule of law," he added.
Mishra accused the chief minister of protecting criminal elements in politics. "Nitish Kumar has campaigned for more than two dozen hardcore criminals contesting the elections from the JD-U and the BJP (Bharatiya Janata Party)," he said.
Communist Party of India-Marxist youth leader Gopal Prasad Sharma said the chief minister had campaigned for many candidates with criminal records.
He named Sarfaraz Alam, Neeraj Kumar Singh and Bucchan Yadav in this category. The charges against the trio include extortion, kidnapping, and murder.
Alam, son of controversial former central minister Mohammad Taslimuddin, is the JD-U candidate from Jokihat. Singh is party candidate from Chatapur while Yadav is contesting from Bihariganj.
The chief minister also campaigned for criminal-turned politicians like Manoranjan Singh alias Dhumal Singh, Sunil Pandey and Anant Singh.
He campaigned for Lesi Singh - wife of slain ganglord Butan Singh - who is contesting from Dhamdaha constituency. Lesi Singh is a former legislator and former chairperson of Bihar Women's Commission.
Interestingly, Nitish Kumar never fails to remind the electorate that the rule of law has been established in Bihar and more than 50,000 criminals convicted in the past five years.
He has also warned of a resurgence of crime if he was voted out.