Plain-clothed and uniformed police will be in the mosh pit at Tasmania's Falls Festival this year in a bid to stop a repeat of the sexual assaults which marred last year's event.

Festival-goers last year reported two sexual assaults in the mosh pit and one rape in the camping area.

The head of the Sexual Assault Support Service (SASS), Jill Maxwell, said going into the tightly packed mosh pit was not consenting to be sexually assaulted.

"The message really is for people to keep their hands to themselves — it would be really lovely to have a Falls Festival without any sexual abuse or any sexual harassment," she said.

SASS' Jill Maxwell said peopled should "keep their hands to themselves". ( ABC News )

"Infants, five-year-olds are taught to keep their hands to themselves, and it just seems really difficult for some adults to understand that concept and I think it's really important that we don't accept that behaviour and report it."

Senior Sergeant Troy Hodge agreed.

"The mosh pit, yes it is designed for close contact, people crowding in," he said.

"What we saw last year was deliberate acts of assaults and that's the behaviour we don't want to tolerate."

He urged any witnesses to speak up.

"We'd encourage anyone who sees that sort of behaviour to report it because the potential victims, or people involved at the time, may not be aware, may not know who did [it]," he said.

"So anyone who sees any behaviour like that is encouraged to come forward at the first opportunity and report it to Tasmania Police.

"Police will be there [in the mosh pit] supervising — they might have a slight jig or two — but they'll be just there supervising the mosh pit.

"Inappropriate behaviour or behaviour that makes someone feel uncomfortable won't be tolerated."

SASS has launched a new education campaign about consent as a result of last year's festival.

The series of posters that each deliver a key message about sexual harassment, abuse and consent and will be displayed in pubs, clubs and other entertainment venues across the state.

Senior Sergeant Troy Hodge says mosh pit assaults will not be tolerated. ( ABC New )

Among the messages is: "Groping without consent is assault."

"We were quite surprised by how many women were saying it's expected that you're groped when you go out at night," Ms Maxwell said.

"They don't actually have to accept that behaviour and that any form of touching without their consent is not OK."

'Buddy up' with a friend

Paramedics at this year's festival will be handing the support service's cards.

Police recommend buddying up with a friend.

"We want people to be safe, [and] if you're aware of a friend or anyone who's been involved in some incident where they have been subjected to any sort of inappropriate behaviour or an assault to come and report it," Senior Sergeant Hodge said.

"If we're aware of it we can take some steps to either prove or disprove something that's occurred, but the main idea is to support anyone involved who ahs been subject to something that they are not comfortable with."

Police urge victims and witnesses to make detail observations of the perpetrators, or even take a photo, and report it to police as quickly as possible.