Brian Booth, Chairman of the West Yorkshire Police Federation, said significant cuts has led to role models, such as police officers in local communities, being lost.
His comments come as the Yorkshire Post can reveal children as young as five have been suspected of a catalogue of serious offences including rape in the last six months.
A Freedom of Information request has revealed that a total of 13 children under the age of 10 have been suspected of rape across Yorkshire from October 2018 to April this year.
Hundreds have also been suspected of other serious crimes including sexual offences, violence with injury and possession of offensive weapons.
Mr Booth said: "I have talked on many occasions on how policing has diversified and demand has increased. This is but one example whereby due to significant cuts in local authority funding, social and child services, the police take on the extra demand to the best of their ability.
"Our officers are often picking up the pieces when other services don’t have the capacity anymore.
Of those children under the age of 10 who were suspected of a crime, none of them could be arrested or charged because of their young age.
Criminal responsibility is the minimum age someone can be arrested or charged for a crime.
In England and Wales, the age of legal responsibility is ten while in Scotland it is eight.
Instead, the most they face is a curfew, a child protection order or being taken into care.
Mr Booth said the power of early interaction with children should never be underestimated.
"He influenced who I am today and we should never underestimate the power of this interaction at an early age.
"Community policing has been decimated over the past ten years and I truly hope with positive investment that it returns for the benefit of us all."
Detective Superintendent Jon Morgan, of West Yorkshire Police’s Safeguarding Central Governance Unit, said offences involving suspects under 10-years-old make up an "extremely small percentage" of overall crime.
He said: "As part of our victim-centred approach, we record all crimes - even where the suspect is immediately identified as a child under the age of 10.
"While a suspect under the age of 10 is under the age of criminal responsibility and therefore will not be subject to the criminal justice process, alongside partner agencies, we will work with them and their parents to address the causes and motivations of their offending. Details of children who have committed offences are shared with the relevant local authority to provide further support as necessary via their Multi-Agency Safeguarding Hubs.