Thursday 7 September 2017 16:22, UK
Maikel Kieftenbeld has returned to Birmingham after the EFL ruled his Deadline Day move to Derby cannot stand.
Kieftenbeld's documents were registered less than two minutes after last Thursday's cut-off point after he initially signed the wrong box on a form.
The EFL ruled the £500,000 transfer invalid earlier this week, and Derby have failed to overturn the decision on appeal.
A news story on the club's website said "we reluctantly accept the EFL's adjudication."
And a spokesman added: "This scenario highlights the challenges of the transfer window.
"All clubs would prefer to complete dealings earlier, but as clubs try to fine tune their squads this inevitably creates last-minute scenarios.
"We would like to place on record our thanks for the help and assistance of Birmingham City Football Club throughout this process."
Kieftenbeld has featured in five of Birmingham's seven games this season, scoring against Bournemouth in the Carabao Cup.
