Organisers the Great Run Company and West Midlands Police chose to cut Sunday's route short after a suspicious vehicle was spotted parked up near Cannon Hill Park.
The Great Birmingham Run saw more than 11,000 brave the harsh weather and take to the city's streets for good causes. It was originally thought heavy rain and flooding caused the route to be shortened.
Organisers later revealed that it was due to the suspicious van parked up and after consultation with police, they closed a stretch of the route of approximately one mile.
But it has now been revealed that the route was shortened by approximately two miles. The distance completed was 11.07 miles – instead of 13.1 miles.
In a note sent from Paul Foster, the chief executive at the Great Run Company, seen by the Express & Star, he apologised for cutting the route short – but added that their priority was to stage the event safely.
He said: "Firstly, I’m really sorry that we had to cut the route short. Almost everyone who took part has been very supportive and understanding, and we truly appreciate that. There have also been a few negative comments on social media and I want to address those, and to provide a few more details about what happened.
"The route was cut short because of a suspicious vehicle parked in a restricted area near Cannon Hill Park. The vehicle was identified only a short time before the start of the race. This was because it was on a stretch of road that didn’t close until later in the morning.
"The van looked suspicious, was from out of town and efforts to trace the driver were unsuccessful. This happened while you were on the start line.
"When a vehicle is flagged like this, a strict procedure is followed, involving us as event organisers and the police teams assigned to the event. For obvious reasons, I can’t give any details of police procedure.
"We delayed the start to try and sort the situation, and we said on the start line that delays were due to flooding. We were still trying to confirm the details, and, for several reasons, we don’t draw attention to a security issue unless we absolutely have to.
"At this point, we decided to close a stretch of the route of approximately one mile. However, as more details came through, it became clear we had to avoid the whole of the Cannon Hill Park and Edgbaston area and so the route was shortened by approximately two miles.
"This wasn’t clearly communicated to the start line and we appreciate that this caused some confusion. We have measured the course since, and the actual distance you ran yesterday was 11.07 miles."
He added: "This was a fast-moving situation, and we had to make decisions quickly. The team were focussed on working with the police to assess the security situation, securing the diversions and rearranging the route so the event could go ahead on a shortened course.
"We were also assessing the route to confirm there were no other security concerns. As I said, our priority was to stage the event safely, and unfortunately some communication to the runners wasn’t perfect.
"This was a difficult situation to manage, but we did everything we could to ensure you were still able to run, even if you were unable to complete the full distance. I am proud that our team were able to quickly react and adapt to the situation and get the event underway safely.
"Every decision yesterday was made in consultation with our brilliant colleagues at West Midlands Police.
"Clearly for many it meant a day you had been training for, and looking forward to, didn’t turn out as planned. We understand some people may be disappointed, but we will always put the safety of our participants, spectators and everyone associated with the event as our top priority."