"To prove the allegations" means to provide evidence or facts that support the claims or accusations being made. It involves showing that what has been said is true or valid. Full definition
Every time something surfaces that points to voter fraud, you can't prove your allegation that it's not happening and always use racism as your cover. (nystateofpolitics.com)
Unlike a traffic ticket, the evidence must simply prove the allegation on a balance of probabilities. (vancouvercriminallaw.com)