More than half of domestic crime victims withdrew support for charges over the last year.

Police said they were doing everything possible to support victims outside prosecution after domestic crime went up almost a quarter to 6,082 against a three-year average of 4,916 in Suffolk.

The increase coincided with a fall in the number being solved – from 26.9% across three years to 17.5% in 12 months to July 2018.

The same trend emerged for serious sex offences – up 23% to 1,655 against an average of 1,346, with about one in 16 solved (6.3%) against an 11.7% average, as almost a third (31.8%) of victims withdrew support for charges.

Performance against objectives in the Police and Crime Plan also showed robbery up 47.8% (from 271 on average to 401 in 12 months) and violence with injury 11.8% higher than the three-year rate.

The local trend falls in line with the national picture, said Suffolk Constabulary, which recorded the second lowest level of domestic abuse (per 1,000 people) of eight similar forces, and the second best conviction rate, as of last March.

Police said increasing society empathy had built confidence in victims of abuse and sex offences to come forward – and that investment in support services was greater than ever.

Changes to recording guidelines had also improved understanding of the scope of abuse in communities, added a spokesman.

“Hidden harm investigations are some of the most complex that are tackled, as by their very nature, they tend to occur behind closed doors,” they said.

“This provides challenges to evidence collection that do not exist in many other areas of criminal investigation.

“Investments in training, use of forensic science and technology are ensuring investigations are carried out to a high standard.”

Tim Passmore, who has invested almost £4million in victim support as police and crime commissioner, said: “I hope and believe the reason for rising demand is that victims have more confidence to do so.

“With the more serious cases – which must take priority – comes an increased level of complexity.

“In the case of robbery, a lot are sadly related to a drug problem we know leads to acquisitive and violent crime. That said, there’s still an issue of victims not talking, which doesn’t help solved rates.

“I believe it’s our biggest threat and I’m determined to tackle it.”