The Rio de Janeiro state legislature voted on Wednesday to open impeachment proceedings against Governor Wilson Witzel over accusations he embezzled funds for fighting the coronavirus pandemic.
With 69 votes in favor and one abstention, legislators in the state - Brazil's second-hardest-hit in the pandemic, after Sao Paulo - passed a motion to open an impeachment commission to investigate the allegations.
It was one of 14 impeachment motions facing Mr Witzel, a former ally of President Jair Bolsonaro, who denies the allegations and accuses the far-right leader of political persecution.
If the commission decides to go ahead with impeachment proceedings, the legislature will hold another vote on whether to suspend Mr Witzel from his job and put him on trial.
That process, which can last up to 180 days, would conclude with a vote on whether to remove him from office definitively.
Mr Witzel, who backed Bolsonaro in the 2018 presidential election, has become one of the President's most outspoken opponents.
The pair have notably clashed over the response to the pandemic. Mr Bolsonaro is a fierce critic of the stay-at-home measures adopted by Mr Witzel and other governors to curb the spread of the virus, arguing they are needlessly wrecking the economy.
Police raided the governor's official residence last month as part of an investigation into the alleged embezzlement of funds to build field hospitals for coronavirus patients, an emergency measure to avoid the collapse of the state health system.
Mr Witzel, 52, again denied wrongdoing. I was elected with the fight against corruption as my pillar, and I will never abandon that flag, he said in a statement.
Brazil is the latest epicenter in the pandemic, with nearly 40,000 deaths, the third-highest toll in the world after the United States and Britain.