It was thought the 31-year-old Commonwealth Games champion had set new British and European records by clocking 30 minutes 18 seconds in the 10,000m road race earlier this month, shaving one second off her personal best.
But organisers of the race, The Great Run Company, apologised for “human error” that meant the course on 2 October was “not laid out in line with the previously agreed plans”.
The company has reportedly been in contact with McColgan to explain and apologise, and said there is “no excuse” for the error.
McColgan admitted she was "disappointed with [the] news" but added: "Thankfully my British and European Record still stands from the Great Manchester 10K. So it’s all good!"
It is not the first time the Newcastle-based company has experienced problems measuring the course. In 2016, the half-marathon route was adjudged to be 149.7m shot, resulting in all records for that year's race to be wiped from the history books.