Domestic violence perpetrators are using sex abuse as a control tactic and weapon to silence their partners in relationships.
Crisis workers said intimate partner sexual violence burdened victims with the shame and social stigma linked to rape, as well as symptoms of post-traumatic stress disorder that often surfaced months after the abuse.
Canberra Rape Crisis Centre director Chrystina Stanford said rape as a tool of domestic violence wasn't often talked about, but it had an insidious impact on victims who were already reeling from other physical and emotional trauma.
"For the women who come to our service who also report domestic violence, sexual abuse is very common," Ms Stanford said.
"Probably what isn't as common is women disclosing it.
"That's why it's important we talk about intimate partner sexual violence and give it a platform, because we're speaking for women at a time when they can't speak for themselves.
Ms Stanford said she had heard of male offenders who forced their partner to engage in sexual behaviours she wasn't comfortable with, or drugged her so she became "sexually vulnerable" to him or his friends.
He might also take explicit photographs or videos, also sometimes involving his friends, and threaten to share them as a tool to quiet or blackmail his partner.
"That's where technology is again the enemy but it's probably not being talked about as much in that way in relation to domestic violence compared to stalking and harassment.
"We're not recognising it as domestic violence."
Ms Stanford said rape within relationships was a particularly powerful "silencing weapon" for women from ethnic backgrounds.
"It's used in a way of forcing them to engage in sexual activity or behaviours they might not be comfortable with, or forcing them to have sex at a time of the month that might be against their culture or religion.
"Or it might be forcing them to engage in sexual acts that are against their culture or religion.
"That's something we're seeing more in our service than we were 20 years ago."
Ms Stanford said domestic violence offenders used sexuality and rape in a variety of ways, but "the bottom line of it is shaming".
"Shame is one of the long-lasting legacies and impacts of sexual abuse.
"The women who come to our service have said the bruises and the physical injuries they know will heal, but with sexual assault comes such a significant impact of shame that that's the thing they carry with them.
"That is what is hardest to heal and that's something that isn't visible to the outside world."
She said the impacts of sexual assault often didn't surface for months, when women would experience flashbacks and were unable to sleep, eat, work or socialise.
"At crisis point when the kids, police and crisis workers are around, that's not what's being talked about. But 12 months later that's what she's having nightmares about.
"People call us and say they're losing the plot but they're not, it's very normal.
"We tell them what happened to them is the thing that isn't normal. But whatever they're experiencing now are the very normal impacts of trauma."
Ms Stanford said she was also aware of sexual offending directed at children in violent domestic situations.
"Some people who perpetrate domestic violence perpetrate that physical violence as a smokescreen for child sexual abuse.
"This particular group of offenders would consider it preferable to be caught and charged for offences related to domestic violence than they would be caught and charged for sexual abuse offences.
"What you're left with is two crises in the family, one where the child is being sexually assaulted, and the violence towards the partner."
"There you have a particularly explosive scenario where everyone is being harmed."
If you or someone you know is impacted by sexual assault or family violence, call 1800RESPECT on 1800 737 732 or visit www.1800RESPECT.org.au. In an emergency, call triple-0.