A freezing elderly couple were trapped in a park for more than an hour after wardens shut the gates while the pair were still inside.
The married couple, who are in their 70s, were sitting on a bench when a Barkingside park keeper locked the gates.
The pair called Redbridge Council for assistance and, when they finally got through, a staff member promised to help, but nobody called them back.
The pensioners were only spotted when an man passing in a car saw the elderly man's bobble hat out of the corner of his eye.
"We were driving past and my missus saw a bobbly bit of hat move in the dark," said Wahab Zaidi, 43.
"She said 'are there people in there?' I went to check and found them shivering and weak.
"They said they had called the council but no one was helping them so I said I would drive home and get a ladder."
Mindful that the couple had been out in the cold for more than an hour, Mr Zaidi rushed back to his property.
On his way, he bumped into a neighbour, who is in the building trade, who offered up his 6ft ladder to help the couple.
Mr Zaidi then rushed back to the park, where he helped them leave the park.
He said: "It took over 30 minutes to get them up the ladder. They were scared they would fall and injure themselves.
"It was good they were able to do it, and then we pulled them over the other side.
"If we hadn't spotted them, god knows what would have happened. They just wouldn't stop shaking - they wouldn't have made it though the night."
Deputy leader of Redbridge Council Kam Rai said: "I was disappointed to learn residents were locked in our park.
"We do ask that the park staff blow a whistle and have reiterated they do this clearly during closing time and ensure no one is left behind.
"It does, however, get dark early and I’m glad the residents were able to be helped out safely.
"If anyone is locked and they cannot get through to the parks team then in an emergency they should also call 999."
A spokesman for Vision Redbridge Culture and Leisure, who manage the borough's parks on behalf of the council, said: “We’re sorry this has happened and want to thank the passer-by for helping out.
"At this time of the year, the locking of Barkingside Rec begins at 4pm and finishes at 4.30pm.
"Part of the process involves wardens blowing a whistle throughout the park for 30 minutes and patrolling by car with hazard lights on as they lock each gate to ensure the park is secure.
"The opening and closing times are clearly displayed on park signs and we would urge residents to adhere to these.
"Thankfully such incidents are rare but we will be checking that existing procedures were followed correctly and whether they need amending to help ensure there isn’t a repeat.”
