A leading urban wildlife expert has told Sky News Online why he thinks a fox attacked two nine-month-old twins as they slept in their bedroom - soiled nappies.
Photo of Lola and Isabella Koupparis from mother's Facebook page
John Bryant believes it was a cub, about three to four months old, which went into the house after being attracted by the smell of food from the nappies.
He said that once the fox realised that the nappies were attached to the youngsters, it panicked and injured the twins.
Distraught mother Pauline Koupparis said she found her daughters Lola and Isabella crying and covered in blood after the fox went into their upstairs bedroom and attacked them in their cots.
They were taken to the Royal London Hospital in east London, but one of the girls was transferred to Great Ormond Street Hospital in central London for further treatment.
Police at the home of the fox attack in Homerton, east London
Doctors said both were in a "serious but stable condition".
Lola has facial injuries and some puncture marks on her arm, while Isabella suffered injuries to her arm and was receiving special care, their mother said. She added the tots both underwent surgery.
Mrs Koupparis described the attack as "like a living nightmare".
Mr Bryant said he has received "lots of reports" from people in urban areas who have found nappies, dragged away from refuse bags, in their gardens.
"Foxes have a grab-and-go philosophy," he said.
"In this case I suspect it was a combination of an open door in the house and the fox cub wandering upstairs attracted by the nappy smell."
He has never known of a fox attacking a human, calling this one a "completely unique event" in his 40-year career. He said it was a "freak incident" which he thought "will never be repeated".
The children's mother Pauline Koupparis
Mr Bryant said he had heard of two similar cases but they turned out to be incidents involving a German Shepherd dog and a cat.
He thinks that people should not leave their doors open at night and should dispose of nappies in a bin rather than leaving them on top of it.
He said: "People leave nappies in the street and there is a lot of food out there for them. It is down to us not to create the conditions for them."
There are thought to be around 30,000 foxes in urban areas in the UK, including 10,000 in London alone.
Another top wildlife expert Terry Nutkins told Sky News Online that he is 75% sure that the attack was not carried out by a fox, saying it was more likely to be a dog or a cat.
He also wants to know more about the injuries of the youngsters. He said if they were scratched, rather than bitten, it was more likely to be a cat.
One expert said the fox attack was a 'freak' incident
Mr Nutkins said: "There is more to the story than meets the eye. Why would a fox attack two people? A fox will attack a human if it is trapped. They won't go out of their way to attack a human."
He was also worried that the case may spark a backlash against foxes.
Mr Nutkins said: "There is a danger of an over reaction. Most people are frightened of wildlife. It does worry me that there will be a campaign against foxes and people will inflict cruelty against them."
The fox is thought to have crept in through a door on the ground floor which had been left open because of the hot weather while Mrs Koupparis and her husband Nick watched Britain's Got Talent on television.
Mrs Koupparis, who lives in Homerton, east London, went upstairs when she heard the girls crying on Sunday night.
She told a radio station BBC London: "I went into the room and I saw some blood on Isabella's cot. I thought she'd had a nosebleed.
"I put on the light and I saw a fox and it wasn't even scared of me, it just looked me straight in the eye.
"It's something I would never expect to happen to anybody, let alone happen to my beautiful girls."
Fox Attack On Two Young Twins: Expert John Bryant Says Fox Attracted By Soiled Nappies | UK News | Sky News