An American politician says he will challenge the results of a local election because he believes the man who beat him is dead and being represented by a body double or robot.

In a letter posted on his personal website, Timothy Ray Murray claims Frank D. Lucas, who beat him on Tuesday to be the Republican nominee for an Oklahoma congressional election, has been dead for three years.

Timothy Ray Murray: claims his political opponent is actually dead. Credit:Mr Murray's website

"It is widely known Rep. Frank D. Lucas is no longer alive and has been displayed by a look-alike," he said.

Mr Murray further claimed there was evidence to show his opponent was executed in Ukraine after being sentenced by an organisation he called the "world court".