Refund calls over Brighton's short half marathon
Runners have called for refunds or discounts after organisers revealed the Brighton Half Marathon has been 146 metres (0.09 miles) short since 2015.
Some took to social media to show their annoyance, and others have said their personal best times had been affected by the news.
Organisers apologised unreservedly for the mistake on Friday.
In a statement, organisers of the half marathon said they were contacted earlier in March by UK Athletics and an ensuing investigation had confirmed the course was too short.
Organisers said a turning point was positioned incorrectly for the last three races.
Race director Martin Harrigan said: "We are a team of runners ourselves so we fully understand the impact."
Simon Dowe, chief executive of the Sussex Beacon charity, which organises the event, said: "We can't apologise enough for this mistake."
Brighton Half Marathon elite race winner Eleanor Davis, from Cornwall, said she ran the race specifically to get a qualifying time for the London Marathon.
She said: "To find out afterwards that it counted for nothing was pretty devastating and concerning, but luckily, the London Marathon have been really kind and waivered it for me, so I can compete."
Chris Mattock was one runner who called for his money back, tweeting: "So no refund despite invalidating the qualifying time that I needed from the Brighton half marathon? Thanks"
James Allen wrote: "So Brighton half marathon course has been 146m short for last 3 yrs! Must be April fools day surely!!#get the basics right#shocking#athletics"
But Matthew Grey posted: "Brighton Half-Marathon : "If we make it 150m or so shorter, people will say 'I always do my best times at Brighton, it's my favourite' ".