Brighton Marathon organisers have apologised to thousands runners on Twitter after it emerged the course was 568m (0.35 miles) too long.
Around 7,500 marathon participants set off from Preston Park on a course they thought was 26.2 miles.
But after runners questioned how long the course was, the organisers released a statement: "We would like to apologise to our marathon participants that the course today has measured 568m too long.
"We are wholly disappointed that this has affected our runners & hope that it hasn’t marred the experience, at what has been a fantastic comeback after event after 18 months."
So far the tweet has had over 150 shares.
Organisers congratulated the first man to finish, Neil McClements, with a time of 2:33:44, with Ollie Garrod coming in second and Mark Innocenti in third.
Congratulations to Neil McClements, our men's marathon winner with a time of 2:33:44.34.— Brighton Marathon Weekend (@BrightonMarathn) September 12, 2021
Ollie Garrod coming in second and Mark Innocenti in third. #BrightonHero #BrightonMarathon2021 pic.twitter.com/qX1GNvNAqd