Great Britain's disqualification from the men's 4x400m relay at the European Athletics Team Championships after a reserve shot putter was named in the line-up by mistake has been blamed on a "technical error".
Youcef Zatat - who had not travelled to Bydgoszcz in Poland - was included in the quartet instead of sprinter Rabah Yousif, and the British team were subsequently prevented from taking its place in the final.
UK Athletics performance director Neil Black told www.britishathletics.org.uk: "It is gutting for the athletes involved.
"There was an error with the declaration process and we are exploring exactly what happened.
"We'll be reviewing with those involved in detail over the next day or so.
"The athletes were amazing. They were informed and took it on the chin.
"It is the worst way to finish the event and we apologise to those who were looking forward to seeing the GB men's 4x400m team doing battle as we know they would have competed with excellence."
Britain finished fifth overall with a total of 302.5 points.
Italy won the 4x400m race and finished fourth in the overall standings with 316 points.
Twelve points were available for each event's winner, with 11 available for second place - meaning Britain would still have finished fifth if they had won the 4x400m and Italy had come second.
Britain's men won the silver medal in the 4x400m relay at the 2018 European Athletics Championships, and took bronze at the World Athletics Championships in 2017.