Lack of training and workload pressures led to offences including rape not being recorded as crimes.

Her Majesty’s Inspectorate of Constabulary (HMIC) found that in one batch of 157 incidents they found 22 that should have been recorded as crimes but were not, as well as three wrongly classified crimes and 19 recorded outside the 72-hour limit.

In another batch of 48 reports on a database that included serious sexual offences against children, they found 14 crimes that should have been recorded, only two of which were done correctly.

Elsewhere they also found six cases in which rape reports were wrongly classified as “no crime” having at first been recorded as a crime.

HMIC sampled the force’s crime records as part of a nationwide inspection into crime figures.

In their report published today, based on data from late 2012 to late 2013, they raised significant concerns and urged Sussex Police to take action.

Both HMIC and the police note that improvements have been made since the inspection was carried out but say there is more to do.

Sussex Police Deputy Chief Constable Olivia Pinkney, inset, in charge of crime data integrity, added “in most cases” the crime would have been investigated regardless of whether it was recorded.

She added: “However we accept that in some instances where we have not recorded a crime, some victims would not receive the support they should have from our partner agencies such as victim support services.

“This is clearly not acceptable and we have made significant changes in expectations and standards around crime recording to make sure that all victims get the correct levels of support that are tailored to their needs. Where we have fallen short I apologise.”

They said they found “no evidence” of “institutionalised performance pressure” not to record crime, and “isolated pockets” of this attitude were disappearing.

Instead they blamed officers’ lack of knowledge about the rules “alongside some pressures of workload”.

They said victims of crime were being “let down” with an “unacceptable” 19% of reported crimes going unrecorded.

In March, the Sussex Police Chief Constable set up a team to improve the crime-recording process.

Police and Crime Commissioner Katy Bourne said the under-recording was “simply not good enough” but praised improvements made.