The number of young police officers in England and Wales has fallen by nearly 50% in two years.
There were 9,088 officers aged under 26 in 2009-10 but only 4,758 in 2011-12, figures obtained by the BBC show.
In Cleveland, North Wales and Staffordshire the fall in the number of officers aged under 26 was more than 70% over the period.
Overall police numbers hit a nine-year low in 2012, due to tighter budget constraints slowing recruitment.
But this data, obtained in a Freedom of Information request by BBC Radio 4's The World This Weekend, shows how much of that fall has been among younger officers.
Cleveland reported a 74% drop in young officers - the highest figure among the forces.
"The reason for the change in the age profile of our officers is pretty simple," said a spokesman for police and crime commissioner Barry Coppinger.
"It is because we have not recruited officers for the past three years - a direct consequence of the funding reductions imposed through the Comprehensive Spending Review.
"In the past we have tended to recruit people between 21 and 25, so the recruitment freeze will inevitably have reduced the share of officers at the lower age bracket.
"This trend is likely to continue until we are in a position to resume recruitment and that is dependent on the funding position."
Winston Roddick, police and crime commissioner for North Wales, said he hoped his first budget would help lead to a substantial rise in recruitment of young officers.
"The current economic downturn has undoubtedly affected the recruiting of new police officers," he said.
"However, during my campaign to be elected commissioner, I identified increasing the number of officers on the streets as one of my five priorities. I believe this will reduce crime and allay public concern for safety."
Olly Martins, the PCC for Bedfordshire, which saw a 58% fall, said the implications of this trend were very worrying.
"To secure policing by consent, and thereby be as effective as possible, forces need to look like the communities they serve.
"This is particularly true when it comes to the need to engage with younger people, who are disproportionately represented both as victims of crime and among its perpetrators."
Overall, there are nearly 10,000 fewer police officers of all ages than there were in 2009/10.
Chris Haselden of the Association of Chief Police Officers said the service faced budget cuts of about 20% over four years.
Added to that, there had been a drive to recruit more graduates and more people with "life skills", resulting in a higher average age of recruits, he said.
An annual fitness test would be introduced in September 2013 to ensure all officers were sufficiently fit to carry out their duties, he added.
A Home Office spokesperson said: "Recruitment is a matter for individual forces and it is for chief constables and police and crime commissioners to ensure they have the right mix of officers.
"Police officers play a vital role in this country, fighting crime and keeping us safe. Our reforms are working - crime is falling and public confidence is high.
"The new college of policing is also now operational, ensuring we recruit top quality police officers and provide them with the specialist skills and training they need."