The home secretary has said that a law on the criminal past of elected police commissioners is not aimed at people such as candidate Simon Weston.
Theresa May spoke as doubts were raised over whether Falklands veteran Simon Weston OBE can run in the election for South Wales Police Commissioner.
As a teenager, he was convicted for being a passenger in a stolen car.
Mrs May said on Tuesday the legislation was not aimed at barring someone who had a conviction at the age of 16.
Mr Weston, from Nelson, near Caerphilly, who plans to stand as an independent, declined to comment.
The war veteran went on to become an author, public speaker and charity supporter, after being badly burned during the destruction of the Sir Galahad during the Falklands conflict.
He has previously spoken about how he was ashamed of his conviction at the age of 14 - for which he was fined - and how it led to his decision to join the Welsh Guards.
The legislation creating the commissioners bars candidates convicted of imprison able offences.
According to the Police Reform and Social Responsibility Act 2011, someone cannot be elected if convicted of an offence which carries a prison sentence, whether or not they were jailed.
Last week, Mrs May said she hoped to see more independent candidates like Mr Weston.
He announced his decision to stand in February, saying the role needed someone who was not a politician.
The 50-year-old, who now lives in Cardiff, said he thought the commissioner should be someone who was not afraid to speak their mind.
The elections on 15 November will create police and crime commissioners in 41 force areas of England and Wales.
Jon Silverman, professor of media and criminal justice at the University of Bedfordshire, said he was very surprised to hear that a teenage conviction could make Mr Weston ineligible.
But he said a close reading of the legislation left no room for doubt.
"It's absolutely clear when you read the wording of the act," he told BBC Radio Wales.
"The fact that he didn't go to prison is irrelevant."
Mr Silverman added that the stringency of the rules for commissioner candidates undermined the government's attempt to attract independent, non-political figures.
"Since Colonel Tim Collins dropped out... we are left with mainly former politicians," he said.
"I think it's a blow if not an embarrassment to the government who wanted a new way of overseeing chief constables.
"In fact the rules are tighter than if you wanted to become a police officer."