The security firm boss behind the Old Trafford bomb scare fiasco who was at home watching the drama unfold on television when Manchester United officials contacted him has admitted "full responsibility" for the "lapse".
Speaking outside his home, Chris Reid, managing director of Security Search Management and Solutions Ltd, said the item was a "mock up of a pipe bomb", which was 20cm long, with "brass fittings at each end".
He revealed it also had a white label which said: "Training aid. If found, contact SSMS on 07*********:"
Manchester United today insisted it is "proud" of yesterday's terror evacuation and blamed the security expert for leaving a fake bomb inside Old Trafford despite telling them all 14 had already been recovered.
United is yet to say sorry 24 hours after 76,000 fans were ordered to leave the stadium just 20 minutes before kick-off.
The terror alert is set to cost United £3million (NZ$6.4m) as club sources admitted the "idiot" who left the fake bomb behind "is in for a right kicking".
Vice-chairman Ed Woodward claimed that the device strapped to a set of toilet pipes and only spotted 20 minutes before kick-off was not picked up by sniffer dog teams because it did not actually contain explosives.
Mr Woodward's statement contained no apology despite Manchester's mayor Tony Lloyd saying the club should be "up front" with fans and "grovel" to them about the "shambolic" security scare.
He said: "The contractor had signed the device as having been recovered along with the 13 other devices at the end of the exercise.
"Once a live situation was identified, the club and police had no option but to treat the matter as a potential terror threat; we could not have assumed it was a training exercise error. Presented with the same situation in the future, we would take the same action".
He added: "The safety of the fans is our number one aim at every event we host at Old Trafford. Overall, I'm proud of how our staff responded".
Mr Reid said tonight: "I was contacted by Manchester United to ask about the training at about 4 o'clock. I was at home watching things unfold - it was first reported that there were two bags, so I made no connection with what had happened on Wednesday.
"I am truly devastated that these people have come all this way, to a very important match at the end of the season. To say I'm sorry doesn't seem adequate, but I am. It is a concern that they weren't found.
"But the regimes they have will be checked to ensure that something like that doesn't happen again, whether it's me or just another bag that's been left."
Mr Reid, a former Met Police counter-terrorism officer previously accused the club of overreacting. He said he is still waiting to hear from Manchester United but admitted he fears he will be "hung out to dry".
The former Met officer who worked on security at London 2012 later told the Telegraph: "Look, I'll be honest, they didn't need to evacuate the stadium. It was an inanimate device".
Fans were left in tears and even abandoned their bags and coats in the rush to leave the ground fearing their lives might be at risk.
But police confirmed that the "bomb" was left at the stadium in error in the days leading up to the game, apparently after an exercise involving a company called Security Search Management and Solutions Ltd working with a sniffer dog team run by Deacons Canines.
Mr Reid admitted he could lose his business over the scandal.
"There's a lot I want to say to the fans, but I don't want to do that now. I've actually spoken to a couple of people who were there and they said don't worry about it, everybody was fine.
"I said as long as no one was injured, and I'm really sorry they had to miss their game."
Mr Reid worked previously for G4S where he was responsible for training guards involved in search and screening vehicles and visitors at the London Olympics.
The company faced enormous criticism and chief executive Nick Buckles resigned after the army was drafted in to provide back up security because the G4S failed to provide the staff needed.
The city's police chief said today that Manchester United must issue a "grovelling apology" for the "outrageous" blunder of failing to spot a fake bomb until just before kick-off.
Police and Crime Commissioner Tony Lloyd says he is shocked the club has yet to say sorry 24 hours after the incident.
Fans sent home yesterday will get free tickets for Tuesday's match but they will have to pay for their own travel, including the thousands who spent huge sums getting to Manchester from opposition Bournemouth, 400km away.
Mr Lloyd said: "I think the club should be grovelingly apologetic. It doesn't seem beyond the wit of us to say if five devices go out, count them back one, two, three, four, one's missing - search from Wednesday until Sunday to make sure you find it.
"But in actual fact this is a bit worse than that because in the event that that had have been a real device, the fact it was only discovered 20 minutes before the kick-off.
"This fiasco caused massive inconvenience to supporters who had come from far and wide to watch the match, wasted the time of huge numbers of police officers and the army's bomb squad, and unnecessarily put people in danger, as evacuating tens of thousands of people from a football stadium is not without risk.?
"So it should have been found in the routine sweep. That's actually why we've got to have proper reassurance that this not only can't happen again but that we know how it's happened in the first place.
"That's not about red faces - it's about giving guarantees to the public, football watchers, United supporters, away supporters, that this is a safe ground - and that our football grounds more generally are places of safety. That's very important."
Manchester United have refused to respond to Mr Lloyd's calls for more information.
Manchester United is investigating. Ed Woodward, executive vice chairman of the club, said: "The safety of fans is always our highest priority. The club takes security very seriously and staff are regularly trained with the police and emergency services to identify and deal with these incidents. We will investigate the incident to inform future actions and decisions."
Yesterday's scare comes less than a month before the Euro 2016 football tournament kicks off in France, with security sources fearful that it will become a real target.
The discovery came only four days after it was revealed that dissident Irish republican groups are again plotting terrorist attacks on the mainland.
On Thursday, Home Secretary Theresa May raised the dissident republican threat - which is rated differently from that of IS and other terror groups - from "moderate" to "substantial".
A Whitehall source said: "Greater Manchester Police really didn't have much choice but to do as they did, given the terror threat level. Football grounds are a target - look at what happened in Paris."
Players from Manchester United and their opponents Bournemouth had been warming up on the pitch when the code red alert was announced. By 3pm all 76,000 fans had been safely evacuated.
One fan said: "The woman who made the announcement telling us to leave the stadium sounded petrified. People left quickly but the tone of her voice certainly gave me cause for concern."