BBC Verify investigates claims spreading online questioning the integrity of the US election.

Republican candidate Donald Trump has repeatedly made claims of election fraud since he first ran for the US presidency in 2016 and he has refused to concede that he lost the 2020 race for the White House

Former President Donald Trump posted to social media an unsupported claim about "massive CHEATING" in Philadelphia, which he claimed had drawn the attention of law enforcement. The Philadelphia Police Department, the Philadelphia district attorney, a Republican city council member and the Pennsylvania Department of State all refuted the claim.

Republican candidate Donald Trump has claimed that there has been 'massive cheating' in the city of Philadelphia in the US election - before an official slammed his comments as having 'no factual basis'.