A Merseyside mum whose daughter was targeted by a paedophile has issued an urgent warning to parents of teenage school children to be vigilante over their internet use.

Her 14-year-old daughter was only saved from the clutches of a convicted child rapist because she regularly checks her mobile phone.

"She was only days away from meeting him and I can't bear to think what might then have happened," said the 35-year-old mum.

The woman, who cannot be identified to protect her daughter, spoke out after 31-year-old Jason Duncan from Wirral was put behind bars for two-and-a-half years.

Judge Mark Brown, who also imposed an extended four-year licence period, described Duncan as a danger particularly to young females.

"It is clear to me that but for the prompt and very vigilant actions of her mother it may well be the pair of you would have met up and goodness knows what might have happened to her if that had taken place," he said.

Liverpool Crown Court heard Duncan was jailed for seven years in 2004 by Forfar Sheriff Court for raping a 15-year-old girl and assaulting another girl of the same age after following her off a bus.

Bernice Campbell, prosecuting, said that during the first two week of April he befriended the school girl via WhatsApp and despite knowing her age they exchanged intimate messages.

He also encouraged her to send topless photographs of herself and sent her an indecent photograph of himself.

He tried to arrange to meet the besotted youngster in a park or the city centre but fortunately her mum checked her phone and realised what had been happening and called the police.

Duncan, of Southcroft Road, Wallasey, pleaded guilty to attempting to meet a girl following sexual grooming. The judge imposed an indefinite restraining order and Sexual Prevention Harm Order.

After the hearing, the girl's mum and step-father praised the police for their speedy action is tracking Duncan down within 24 hours despite only having his first name.

"We knew he had previous convictions but not what for until it emerged during the court hearing and it was chilling," she said.

"I think every parent should check what their children are doing on the internet and I think there should be restrictions on phone apps.

"Many of these internet sites rely on the user just ticking a box saying they are 18 and there are no checks.

"Predatory people like Duncan take advantage of social media and parents must be on their guard for the sake of their kids.

"Our daughter has been badly affected. I regularly check her phone but because of changes in her behaviour and sadly my fears were borne out," she said.

Detective Constable Michael Moran, from Merseyside Police's child sex exploitation team, said: "Today's sentence should send out a very clear message to paedophiles that they cannot hide behind the anonymity of technology to commit crimes against children and they will eventually be caught.

"I would like to praise the mother of the victim for reporting the matter to the police after noticing some unusual activity on her daughter's phone and the victim herself for having the courage to come forward and tell us about the grooming Jason Duncan had subjected her to.

"The victim has shown immense bravery in giving evidence to help secure justice and has been supported every step of the way by the police and our partners.

"I would urge other victims of sexual offences, whether they are historic or otherwise, to not suffer in silence and instead tell someone what has happened to them.

"The force is committed to the protection and wider safeguarding issues of children. In doing so we view the abuse of any child as unacceptable and will work with partner agencies to investigate and where possible prevent such abuse.

“We all have a duty of care to protect young people from harm and I would encourage parents, grandparents, teachers, health professionals, social services and any other adults to take a little time to better educate themselves about online safety and child sexual exploitation.

"Merseyside Police has a great website called www.listentomystory.co.uk which highlights these issues from young people’s perspectives and also shows where you can get help if you have any concerns about any child you know.

"It helps victims to find the right kind of support and advice if they have suffered abuse in the past. It also has loads of information for young people to help them if they think they are being exploited, or if they are worried one of their friends may be."