The rise in the sex abuse of males carried out by women has been noticed by the 'Swedish Organization against Sexual Abuse, Hopp, which helps victims of sexual abuse and assault.
Despite this development, official reports of men who have been abused by a female perpetrator are still very rare, which may in part be due to the large numbers of men who choose to remain silent about their plight.
The men seeking therapeutic help are often extremely ashamed of their situation, Hopp psychotherapist Lena Lindblom told Sveriges Radio.
"We receive emails or calls from men and many are incredibly ashamed and feel utterly degraded."
"80 percent of men who have experienced sexual abuse have been abused by a female, most often by their mother."
Hopp estimates that about a quarter of those they help today are men, a figure which does not match up with current crime statistics.
Although there has been an increase in female offenders, only 2 percent of registered sexual assaults or abuse have been carried out by women.
Karolinska Institutet's sex crime researcher Niklas Långström told Sveriges Radio that he was not surprised by the figures presented by Hopp.
"Yes, it could me more common than we believe. There could be a lot of hush hush and it could well be that maybe 10-15 percent of all people who have carried out sexually offensive actions may be women or girls."
Långström also argues that society has a hard time seeing women as sexual predators.
"People either cannot or do not want to admit that women are also capable of this type of offence."