Bihar BJP MLC Sunil Kumar Singh died of the coronavirus at AIIMS Patna on Tuesday, an official said.
Mr Singh was 66. He is survived by two sons, a daughter and wife.
He is the first lawmaker in the state to die of COVID-19.
"Sunil Kumar Singh today died of coronavirus disease. He was suffering from diabetes and hypertension and was on ventilator," AIIMS COVID-19 Nodal Officer Sanjeev Kumar told PTI.
Mr Singh, who was BJP MLC from local self area constituency from Darbhanga, was undergoing treatment at the hospital since July 13 after he tested positive for COVID-19, the nodal officer said.
Chief Minister Nitish Kumar, his deputy Sushil Kumar Modi, Bihar Legislative Council Acting Chairman Awadhesh Narayan Singh and a host of other leaders expressed grief over the death of the MLC.
In his condolence message, Mr Kumar said the MLC was very popular among people and had interest in social work, an official release said, adding that his death has caused an irreparable loss to politics and society.
The chief minister also talked to his son Sujeet Kumar over phone and consoled him.
Six lawmakers in the state, including the legislative council acting chairman, have tested positive for COVID-19.
Bihar minister Vinod Kumar Singh, BJP MLA Jibesh Kumar Mishra, Congress MLA Anand Shankar Singh, RJD MLA Shahnawaz Alam and JD(U) MLC Khalid Anwar have also tested positive for COVID-19.
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