Organisers of the Brighton Half Marathon have apologised after it emerged the course has been 146 metres or 479 feet short for the past three years.
An inquiry was launched after runners reported that data recorded on their tracking devices failed to measure up to the 13.1-mile distance.
UK Athletics contacted Brighton Half Marathon organisers following concerns about last month's race, and it has emerged the course had fallen short by 146m or 0.09 miles since 2015.
The area of concern centred on a turning point just after mile four where the course passes the independent Roedean School before turning and heading back towards Brighton.
We have concluded that the eastern turning point has been positioned incorrectly over the last three half marathons, resulting in a shortfall in the overall half marathon distance. We are devastated that this mistake has happened and apologise unreservedly to all runners who took part in the affected race years.
The news means that runners face having their personal bests, records and race times affected. And officials admitted the error was likely to have overshadowed the event for many.
DJ Norman Cook, aka Fatboy Slim, launched this year's marathon, marking the 27th year of the race, which raises funds for the Sussex Beacon, supporting an HIV care centre in Brighton.
They're off! Reading half marathon is underway raising millions for charityRead the full story ›
More than one and half thousand runners from across the country took to the streets of Kent on Sunday.
It was for the 34th annual Tunbridge Wells Half Marathon.
Organisers, Tunbridge Wells Harriers, say the weather conditions were ideal as runners paced through the town, crossing the rivers Medway and Eden.
Video credit: Xcell Arial Surveys
The race was won by James Connor of Kent Athletics Club in a fast time of 1:08:50.
Last runner to cross the line was Kate Knight in 3:31:05 who had braved the marathon, walking most of the way, despite a knee issue.
Organisers say the half marathon has raised in excess of £150,000 for charities over the years.
Final preparations are underway for this year's Reading half marathon.
The thirteen mile race takes place tomorrow, starting and finishing at Green Park. More than 19,000 runners are expected to take part.
Three and a half thousand people have taken part in the Hastings Half Marathon. The event is now in its thirty second year and attracts fun runners as well as athletes from around the world. The majority of participants are raising money for charity but some use it as a warm up for other marathons and major races. Tom Savvides reports
Thousands of runners are lining up in Maidenhead ready for this year's half marathon.
The route will start and finish in Maidenhead town centre and take a scenic route through the surrounding areas.
Runners in the 2011 inaugural race keep their race number for the future of the race. Once they have run the race five consecutive times their number will change to gold indicate their achievement to all.
Tickets to take part in next year's Brighton Half Marathon have sold out in record time.
The event is celebrating it's 25th anniversary next February in which 12,500 runners are due to take part.
The race helps raise funds for the Sussex Beacon, a hospice for people living with HIV.
Runners make the most of the sunshine, as they raise money for the Oakhaven Hospice in Lymington. More than £40,000 has been raised with the John Austin half-marathon, since the race was founded three years ago.