The number of offences reported in the nine months between April and December compared to the same period the previous year rose from 789 to 945.

Edinburgh’s top cop attributed the surge to historical offences – now accounting for 40 per cent of complaints.

“It’s one area that’s up significantly for us and it’s about the trust and confidence victims have to report it – which is a positive,” said chief superintendent Gareth Blair.

The rise in sex crime has been put down to higher reporting of historical abuse. Pic: Shutterstock/Police Scotland

“The increase is in non recent cases, so over one year old. It’s not an increase in live-time incidents which are pretty stable.”

Rapes, including attempts, were up slightly, from 167 to 169, while sexual assaults increased from 227 to 283. Lewd and libidinous acts were also up from 59 to 74.

Mr Blair encouraged victims of any sexual assault to come forward and report the crime to his officers.

“Whether it’s a non recent or a live case, it gets the same level of investigation though there’s less opportunity with non recent because there’s no CCTV or DNA,” he added.

Reports of sexual exposure were also up, though numbers remain low, from 29 to 43 cases.

Cyber sex crime is also on the rise as cases of threatening to disclose intimate images – or so-called “revenge porn” – up four-fold from 13 to 52 complaints.

Mr Blair praised his officers for a rise in detection rates for rape, with nearly half, 41.9 per cent, now solved – up 6.6 per cent year-on-year.

Campaigners said many sex attacks are never reported and encouraged traumatised victims to come forward.

“Rape and sexual assault continue to be under reported so it is difficult to tell if increases are due to more incidents taking place, or people having more confidence to speak to the police about what has happened,” said Sandy Brindley, chief executive of Rape Crisis Scotland.

“It’s important that people know that no matter when it happened, the police will always take reports of sexual assault or abuse really seriously.”

Overall, crime was down 3.4 per cent – with 40,746 complaints compared to 42,134 the previous year.

Violent crime was down slightly overall from 656 complaints to 649 though serious assaults were up eight per cent from 291 to 315.

Robberies were down 18 per cent from 226 to 185 with Mr Blair praising targeted policing for the drop.

Extortion, including threats, was up more than half (59 per cent) though numbers remain low, from 32 complaints to 51.

Mr Blair attributed the rise to online based cyber crime with victims often targeted from abroad.

Typical cases see men engage in virtual sex acts online before being told to pay up or have their secret exposed.

Anyone affected by sexual violence can contact the Rape Crisis Scotland helpline on 08088 01 03 02 open every day from 6pm to midnight.

Reports of sex crime in Edinburgh are up by 20%