A toddler aged just three has been questioned by police for allegedly sexually abusing another child, it has emerged.

The youngster was spoken to by officers over claims of 'sexual activity' with two other children aged seven and five, in a case recorded by Durham police.

It emerged as part of research which revealed the number of children questioned over illegal sexual activity with other children had doubled in three years from 555 in 2013 to 1,047 in 2015.

Research has found that the number of children questioned over illegal sexual activity with other children has doubled in three years from 555 in 2013 to 1,047 in 2015 (file picture)

The Sun on Sunday reports that police are increasingly questioning youngsters about alleged sexual abuse of other children.

It says the figures would be even higher had London's Met police not refused to disclose any cases it had recorded.

Youngsters aged under five were identified as criminal suspects by three police forces - West Mercia, West Yorkshire and South Wales, according to the Sun on Sunday's home affairs correspondent Tom Wells.

The newspaper quotes Barnado's chief executive Javed Khan as saying: 'Children abusing other children is deeply worrying.

'They're getting distorted ideas from images online or, tragically, because they've been abused themselves.'

It comes a month after new figures showed a total of 70 sex attacks were committed by children under 10 last year.

A toddler aged just three has been questioned by police for allegedly sexually abusing another child, it has emerged (file picture)

The figures showed how scores of children carried out alleged sex attacks but could not be prosecuted because they were under the criminal age of responsibility.

The NSPCC warned at the time that many of the child offenders could be suffering from abuse themselves.

A spokeswoman said: 'It is deeply concerning that so many very young children are said to have committed sexual offences.

'In these cases we have to question the environment in which they are growing up that has led to them behaving in this way.