RAPE offences in Yarra Ranges increased by 75 per cent in the past year, according to the latest crime data.
The Victoria Police statistics released last week show there were 49 rapes reported, up from 28 in 2010-11.
But Yarra Ranges' Acting Inspector Allan Price said there was no need for community concern because the statistics often meant more victims were confident about coming forward to report what was usually an under-reported crime.
"Sometimes it is about historical offences that are only being reported now."
Inspector Price said police were continuing to focus on high-risk community locations and were always looking to drive down crime rates.
"Victoria Police is very serious about violence against women and children. We do put a lot of time and effort into that area now and we would always encourage people to come forward and report a crime."
Centre Against Sexual Assault forum spokeswoman Carolyn Worth agreed it was more likely people were reporting such offences more.
"It looks like the whole society is going downhill but it's not," she said.
"There are three things that are important: people are reporting it more, agencies and people working together and breaking the silence."
Women's Health East chief executive officer Kristine Olaris said the reported numbers were fairly small, making it hard to know if the changes from year to year were statistically significant — and it was therefore more important to look at the trends over time.
"Reported levels of sexual assault generally bear no resemblance to actual incidence levels.
"This is partly because the overwhelming majority of sexual assaults are not reported and also because it sometimes takes women a long time to report - days, months, weeks or years. In addition, sexual assault is most likely to occur in the home and may be a part of a larger picture of domestic violence."
"As such incidents of rape may not be stand alone events. So there may be more rape offences than rape victims as some victims report repeated incidents."
The crime statistics showed only a minor increase in non-rape sex crimes, from 128 offences in 2010-11, to 130 in 2011-12.
To access CASA's services call 1800 806 292.
To read more on crime statistics for Yarra Ranges, go to yarrarangesweekly.com.au.