Missouri's Republican Attorney General Andrew Bailey said on Thursday he was launching an investigation into Google over allegations that it was censoring conservative speech.

Republicans have long claimed an anti-conservative bias on social media platforms. Tech firms have denied their platforms censor conservative voices.

Google did not immediately respond to a request for comment.

Republican presidential candidate Donald Trump, who is in a tight race for the November 5 presidential election against Democratic Vice President Kamala Harris, said last month he will seek the prosecution of Google if he wins the election.

Trump and his supporters have alleged without evidence that Google searches displayed only "bad stories" about the former U.S. president.

"I am launching an investigation into Google - the biggest search engine in America - for censoring conservative speech during the most consequential election in our nation’s history," Bailey said in a post on social media platform X. His post did not cite any example or evidence for his censorship claim.