The number of arrests for theft in Gwent has fallen by more than a third in the last five years, new figures show.
In August, former Home Secretary Suella Braverman said every theft must be investigated, adding it was "completely unacceptable" that some crimes have been effectively legalised.
Last month, police, retailers and the Government launched the Retail Crime Action Plan to improve response times to retail-related crime, including theft and shoplifting.
This was down from 1,263 in 2017-18, meaning the number of theft arrests has fallen by 45% in the last five years.
However, the number of theft offences logged fell by just 26%, from 16,252 in 2017-18 to 12,042 last year.
Decreasing arrest figures followed the trend across England and Wales, where the number of arrests fell by 37% to 88,914 over the same period.
Ms Braverman told BBC Breakfast: "There is no such crime as minor crime – whether it's phone theft, car theft, watch theft, whether it's street-level drug-dealing or drug use, the police must now follow every reasonable line of inquiry."
Chief Constable Amanda Blakeman, council lead for acquisitive crime at the National Police Chiefs' Council, said: "We recognise how invasive and traumatic it is to be a victim of burglary and theft, and we are already investing significant resources in preventing and investigating serious acquisitive crime.
"Burglary levels have fallen by 51 per cent over the past decade due to this increased investment, and all police forces in England and Wales are now attending every home burglary.
"It is for individual Chief Constables to manage demand within their force and prioritise their resources, drawing on the support of national standards and guidance.
"We do not consider anything to be 'low-level' crime. Each and every crime will have an impact on victims, and this should never be underestimated."
Charge rates for thefts are very low, with just 4.4% of offences with a recorded outcome resulting in a charge or summons nationally in the year to March.
In Gwent, 7.3% led to a charge or summons.
A Home Office spokesperson said: "Since 2010, our communities are safer, with theft offences down by 47% and robbery down by 81%.
"We have also delivered more police officers in England and Wales than ever before and the police have committed to attend all home burglaries and pursue all reasonable lines of enquiry to ensure more crimes are solved and public confidence is improved."