A mum has told how a heroic off-duty police officer saved her young daughter from choking to death on a snack.

Lucie O'Malley, from Chartham, checked on two-year-old Aibhlínn in her pram and was horrified to see her wide-eyed and with purple lips.

The 34-year-old NHS worker immediately lifted her out, started slapping her on the back and screamed for help from other shoppers at Westwood Cross in Broadstairs.

Police officer Nick Bines then arrived "out of nowhere", took Aibhlínn in his arms and told Lucie to call an ambulance.

He took over first aid and managed to dislodge the food.

"He saved her life," Lucie told KentOnline.

"I don't want to think what would have happened if he wasn't there."

The terrifying incident unfolded on Monday morning.

Lucie had gone with her family to the Thanet shopping centre so her other daughter Mai, five, could have a go on the recently-opened Clip 'n' Climb centre.

Husband Ciaran stayed there with Mai while Lucie took Aibhlínn for a walk in her pram.

The little girl had snacked on some berries and cucumber and her mum then gave her some "baby crisps".

As they walked across the retail park, near the Body Shop, Lucie suddenly stopped.

"Something just told me to check on her - she was in a front-facing pram," Lucie said.

"Something just didn't feel right.

"I looked and she was going blue. It was obvious she was choking.

"Her lips were a horrible purple colour and she was wide-eyed and in distress.

"I screamed for help and got her out of the pram and started to do back-slaps."

Lucie, who works for the Kent Community Health Trust helping people with learning difficulties, is first-aid trained.

"But when it's your own child it's a completely different scenario," she said.

"You don't have the same sort of calm approach.

"It was very scary. It's every parent's worst nightmare."

Within seconds PC Bines, a Met Police officer who was off-duty at the time, appeared by Lucie's side after sprinting from his car.

"He said, 'Give her to me, I'm a police officer, I know what to do," said Lucie.

PC Bines put little Aibhlínn over his knee and was continuously "hitting her back and checking".

"He felt her do a big inhale and kept rubbing her back and that's when all the food stuff and phlegm came up," said Lucie.

Lucie was "saying 'thank you' constantly" to PC Bines, who lives near Dover, as they waited for the ambulance to arrive.

"He said he had come to Westwood Cross with his wife and daughter," she said.

"He had seen from his car that we were in trouble. He leapt out of the car and ran across the road to help us.

"It was way above the call of duty."

The ambulance arrived within 10 minutes and took Lucie and her daughter to the QEQM Hospital in Margate for checks.

"I can't ever express how grateful we are to him..."

It was only once they arrived at the hospital that Lucie was able to ring Ciaran - who had no idea what had just happened.

"As far as he was concerned we were still shopping," she said.

Lucie says she had been in "a bit of daze" and once she calmed down she wanted to thank PC Bines properly.

She posted on social media and hundreds of shares later was able to track him down.

"The power of Facebook led him to us," she said. "It can be vile but it does have its good points."

Lucie has been able to message PC Bines but would like to say thank you face-to-face.

"I can't ever express how grateful we are to him," she said. "I'm so relieved he was there.

"There are not enough positive stories about the police and I want him to be recognised for what he did."

PC Bines, who has worked at Bromley Police Station for eight years, said: "I'm the father of a young girl and I know that it's every parent's worst nightmare for their child to stop breathing.

"As a police officer we are regularly first at the scene of challenging incidents where we need to provide emergency first aid. My instinct and training kicked in and there was no doubt in my mind that I needed to step in to help the child.

"I am grateful to the child's mother for getting in touch with me and I'm pleased to hear the she has made a full recovery."

Superintendent Rob Shepherd, responsible for response policing in south London, said: "I would like to commend Nick for his actions during what would have been an incredibly frightening experience for this little girl and her family.

"It's another example of officers going above and beyond to protect people whether they are on or off-duty. To me, stepping up to help people in their time of need is the very essence of what makes us police officers."

Hundreds of people have praised PC Bines' heroics on social media, including Met Inspector Rita Jones.

She tweeted: "Proud to say I’m this officer’s Inspector. He is a hero although he wouldn’t admit it, right place right time.

"Last week another one of my PCs received a commendation for saving the life of a man who had a heart attack, again off-duty training kicks in.

"I do work with heroes."