Inspectors have found “many positive features” in the way Cambridgeshire police operates its custody provision - including the cells at Huntingdon.

But the inspectors, from HM Chief Inspector of Prisons and HM Inspector of Constabulary, were concerned about a lack of control over the day-to-day custody function after a merger of services with Hertfordshire and Bedfordshire.

Their report, which has just been released, follows a snap inspection last August.

Inspectors said the force had improved its work in relation to mental health, ensuring that few people were held in police cells as a place of safety under the Mental Health Act and they were “reassured” that the use of force in custody was proportionate. Peter Clarke, chief inspector of prisons, and inspector of constabulary, Dru Sharpling, said: “We found that detainees in custody were held in reasonably good physical conditions. It was clear that the staff culture remained healthy and we were generally impressed with the care and attention that staff showed towards detainees.”

But they made clear concerns over complex governance arrangements for custody in Cambridgeshire following collaboration in which Hertfordshire took lead responsibility for provision of custody.

Peter Clarke and Dru Sharpling said: “Given the complicated governance structure, and because procedures were in a state of transition, we did not believe that Cambridgeshire had sufficient governance and control over its day-to-day custody function.”

Inspectors were also concerned to find that minimum staffing levels within custody suites in Cambridgeshire were not always complied with, saying: “Staff cover was sometimes not sufficient to ensure safe detention, and this could have had an adverse impact on detainees.”

Overall, Peter Clarke and Dru Sharpling, added: “We found many positive features in the way that custody services operated, delivering good frontline outcomes for detainees in a number of key areas.

“However, at a strategic level, we had concerns that the weaknesses identified in our 2011 inspection remained, and that, in practice, the collaborative arrangements for custody services did not provide sufficient accountability at senior officer level in Cambridgeshire Constabulary. Until this is addressed, we believe that this will remain a block to the custodial function in Cambridgeshire becoming even better.”

Assistant Chief Constable Dan Vajzovic said: “Overall the inspection carried out by HMIP and HMICFRS into Cambridgeshire Constabulary’s custody suites has been positive.

“We welcome their recognition that we have good levels of care and concern for the most vulnerable people we deal with and that, through effective partnership engagement, we have a strong focus on protecting and diverting vulnerable people from custody.

“We have worked hard since the last inspection in 2011 to focus our efforts on reducing the amount of time children spend in police cells and protecting those with mental health problems.”

ACC Vajzovic said: “We acknowledge the inspector’s area of concern and the recommendation, which we will be looking at, and we are already putting plans in place to improve in the areas highlighted.”