Her Majesty’s Inspectorate of Constabulary (HMIC) found 22 per cent of detective posts were vacant, describing it as a ‘national crisis’.

The report from four years ago made it abundantly clear that urgent work was needed to address the causes of why the once highly-sought-after role had lost its appeal and what to do about it.

The topic was discussed in the ‘Investing in Investigators’ session on day two of the Police Federation’s Annual Conference, hosted by Glyn Pattinson, Chair of the Police Federation National Detectives Forum.

DCC Jason Hogg, the NPCC Lead for Investigator Resilience, outlined some of the reasons why fewer people are volunteering for CID roles. This includes high workloads, increasing complexity and impact on work life balance. Some officers are also faced with a £1,200 pay-cut to move from response to a detective role.

Mr Hogg said: “We’ve done a great deal of work through the Recruitment and Retention of Investigators working group in overseeing the development of new specialist routes. Every force has a developed action plan for consideration by HMIC and we’ve encouraged forces to provide target bonus payments. A number are doing these bonuses very well.”

Mr Hogg has developed a national staff bank pilot in Wales, where retired officers are brought in to tackle non-recent investigations. This is “working really well” and should be rolled out nationally.

His own force, Thames Valley, consistently had 50 detective vacancies and now has three. Mr Hogg talked about the work that was done in promoting the detective role and covering the costs of books for officers studying and giving time off – plus a bonus payment.

Det Chief Superintendent Martin Brunning, who also responded to questions in the session, said the launch of the Oscar Kilo Toolkit on 21 June could be transformative in terms of improving the emotional wellbeing of detectives and stop them leaving.

He said: “This is not a one size fits all or a token gesture. It’s got real substance as it comes from group of people who have been through the pain of having colleagues crashing and burning.”

The session also touched on flexible working as one of the factors which had made the difference to recruitment and retention of detectives in Thames Valley – it is “absolutely worth it” Mr Hogg said, “We promoted flexi working and job sharing. This is one of the reasons we have more than 50 per cent women applying for our roles.”