An urgent inquiry has been called after Manchester United’s final game of the season was abandoned due to the discovery of a fake bomb used in a security exercise.

Greater Manchester Mayor and police and crime commissioner Tony Lloyd called for a full inquiry into the “fiasco”, saying it was necessary to find out how the dummy explosive was left behind by a security company.

On Sunday, the game between Manchester United and Bournemouth at Old Trafford was postponed after an apparent explosive device was found in a toilet close to kick-off.

The stadium was evacuated immediately and a controlled explosion was carried out on the suspicious device.

Police said it was a training device that has accidentally left by a private security firm after an exercise that involved explosive search dogs.

“It is outrageous this situation arose and a full inquiry is required to urgently find out how this happened, why it happened and who will be held accountable,” Lloyd said.

He added that the incident caused massive inconvenience to football fans, wasted the time of a large number of police officers and army bomb disposal experts  and put people in danger as evacuating people from the stadium was not without risk.

Christopher Reid, the head of the Security firm that left the fake bomb, said the football club over-reacted in evacuating the stadium and could avoided postponing the game at a cost of £3 million.

The match was rearranged for Tuesday.