A scheme covering the use of stop and search tactics by police should be revised to extend authorisations of a controversial power to lower ranks in exceptional circumstances, according to a watchdog.
Under section 60 of the Criminal Justice and Public Order Act 1994 officers can stop and search individuals without needing to have reasonable grounds for suspicion.
The Act specifies that police of inspector rank or above can authorise the use of the power for a fixed time in a designated area - providing they reasonably believe that incidents involving serious violence may take place or that dangerous instruments or offensive weapons are being carried.
However, while legal, where such authorisations are made by officers of a rank below senior officer, forces would not be compliant with the Best Use of Stop and Search (BUSS) scheme.
Launched by the Home Office and College of Policing in 2014, the scheme placed the level of authorisation at above chief superintendent.
In a new report, HM Inspectorate of Constabulary (HMIC) recommended that it is revised to allow officers of inspector to chief superintendent rank to authorise the use of section 60 powers.
This would only be permitted in "exceptional circumstances" where there is an "unforeseeable and urgent need for an authorisation to protect the public and/or officers", and when a senior officer is not available.
HM Inspector Mike Cunningham said: "We believe that, in very exceptional circumstances, more flexibility with safeguards would be operationally beneficial.
"This is specifically in regards to the authorisation of the use of no-suspicion searches, when serious violence is anticipated.
"We also recommended revising the feature of the scheme which outlines how forces should monitor the use of stop and search powers, to include minimum monitoring standards."
HMIC made the recommendations as it published the findings of a re-inspection of 13 forces previously found not to be complying with three or more requirements of the BUSS scheme.
They were Cambridgeshire, Cheshire, Cumbria, Gloucestershire, Lancashire, Leicestershire, Lincolnshire, Northumbria, Staffordshire, South Wales, Warwickshire, West Mercia, and Wiltshire.
The watchdog said that all 13 services have now achieved full compliance.
Alec Wood, National Police Chiefs' Council strategic lead for operations, said: "As long as a minority of people continue to arm themselves and use violence to steal property or harm others, stop and search is a vital power for the police to protect people.
"Stopping and searching people is an intrusive police power that must be used professionally and legitimately.
"The actions in the Home Office Best Use of Stop and Search help us to ensure stop and search is being used effectively and fairly based on intelligence, so I am pleased that these forces are now complying with the scheme."
Prime Minister Theresa May launched an overhaul of stop and search when she was Home Secretary after the powers were mired in controversy.
Official figures have indicated that black people or those from ethnic minority backgrounds are more likely to be stopped and searched than white people.
Overall, the use of stop and search has been declining. Stops of individuals from black and ethnic minority groups fell by 68% from 2010/11 to 2014/15.