Police want restrictions on using pay-as-you-go phones anonymously in a bid to cut down on county lines drug gangs, according to a report.

Officers suggested people "should have to register personal details when buying a mobile phone or replacement SIM card" to prevent the handsets and numbers being used for drug dealing, the findings by the Her Majesty's Inspectorate of Constabulary and Fire and Rescue Services (HMICFRS) said.

In its report looking at how forces tackle so-called county lines drug gangs, inspectors recommended the Home Office carry out a review of the criminal abuse of mobile phones which should "explore" the regulations of the communications industry, adding: "The present arrangements that enable criminality by allowing the anonymous acquisition of phones and numbers, should be re-examined."

Former detective Mark Powell, one of the HMIC inspectors who worked on the report, told reporters the "impression" from officers they spoke to was that restrictions on buying phones anonymously would be "welcome".

He said: "Officers have to resort to lengthy investigations to try to prove who had a phone.

"But clearly there's a wider debate to be had.

"We are not saying anonymity should no longer be available to everybody but we are saying there needs to be a review of the criminal abuse of mobile phones", adding that this should look at whether regulations need "strengthening" - but this was "not the end of pay-as-you-go".

Chief inspector of constabulary, Sir Thomas Winsor, said: "People regard their communications as a species of privacy that should not be intruded into.

"That's why we say the matter should be considered."

There was "little support" among officers for the use of court orders which block phones and numbers suspected of being used for drug dealing because dealers "obtain replacement phones and numbers quickly and anonymously".

Latest analysis suggests there are more than 2,000 individual deal line phone numbers in the UK, linked to around 1,000 county lines.

In one instance, officers told inspectors a drug gang received and shared a new phone number within an hour of the service provider acting on an order.

A dedicated team proposed by the National Crime Agency to co-ordinate the use of such orders should be set up while the review is carried out, the report added.

Latest analysis suggests there are more than 2,000 individual deal line phone numbers in the UK, linked to around 1,000 county lines.

London, Birmingham and Liverpool are the main exporting areas, with other county lines originating from a further 23 forces, inspectors said.

The term county lines is used to describe gangs and organised criminal groups distributing drugs from typically larger cities to smaller towns around the country using mobile phones to arrange deals with suppliers and buyers.

The gangs typically coerce children and vulnerable adults to move and store the drugs and money.

Also in the report, inspectors suggested those excluded from school could be some of the most at risk of being targeted, and also raised concerns about how those considered vulnerable who had been drawn into the gangs were handled by police.

Inspectors felt the current structure of 43 forces could be hindering how successful police were at tackling county lines and said forces must work together more.

Mr Powell said the HMICFRS recommendations, if adopted, would result in "fewer individuals slipping through the net".

Sir Thomas added: "It will save lives from being shattered by crime and exploitation."

The Home Office said it is considering the report's recommendations and the use of court orders to block mobile phones involved in drug dealing is being reviewed.

A spokeswoman added: "We are investing £20 million to further disrupt county lines activity and established the National County Lines Co-ordination Centre, which has so far resulted in more than 2,500 arrests and the safeguarding of over 3,000 vulnerable children and adults."