A same-sex couple who had their car tyre punctured and a note left outside their home calling "lesbianism an abhorrent practice" is encouraging anyone else targeted in the same way to speak out and notify police.

Kate and Jenny (not their real names) found the typed-out note outside their home to the north of Brisbane this past Wednesday morning.

Along with a picture of the rainbow flag crossed out, it read:

Lesbianism is an abhorrent practice; a vile perversion that is often accompanied by mental health problems including substance abuse, depression and higher levels of domestic violence than heterosexual couples. Sickheads! Depraved sexual practices lead to self-destructive attitudes. Get away from the filth!

The same morning they noticed one of the car's tyres had been punctured with a knife.

"It was out of the blue. It was shocking and upsetting. We've been worried and stressed as a result of this," Kate said.

"If it was when we were in bed, then it was right outside our window and our window was open, and that sort of freaks us out that someone was there with a knife.

"Forensic police came around to take photos and prints, and they said they hadn't seen a note like that."

The couple, who have been together for three years, have only been at the address, on the Redcliffe peninsula, for the past 10 months.

They said they have no idea who could have done it.

"It's just out of the blue. There's another [same-sex] couple that live a few doors up on the other side of the street, they've been here for 10 years and they've never had any issues. So it's really weird," Kate said.

Both of the women have children from previous relationships.

Their two boys were home on the night the note was left and the tyre punctured.

One of their tyres was cut with a knife. ( Facebook )

Jenny said as a result of the incident they have already installed security lights and security cameras, and will be getting quotes for fencing.

"We just don't have the money for it, but we've got to do them," Jenny said.

"We haven't opened the bedroom window at night since it happened, because we're worried to do that.

"They were out there with a knife, right next to our bedroom window. If they're willing to do that, what else are they willing to do? You just don't know.

"It would put us as ease to know who it is, we might never find out why, but we're hoping to."

The couple hope by sharing their story they will encourage others who may have received the same note to speak out and notify police if they have not already.

"We put it out there a bit to see if anyone else in our area has received any kind of notes like this," Kate said.

"If it happened to someone else and they're too scared to say something, to know it's happened to someone else they may come forward and let the police know."

A Queensland Police Service spokesman said the matter was still under investigation.

"We encourage anyone with information regarding the matter to contact police," the spokesman said.

'The people who do this are cowards'

Parents and Friends of Lesbians and Gays Brisbane spokeswoman Shelley Argent said it was a horrendous letter.

"Something similar happened in Mackay recently. I think a lot of this is spin off from the postal survey we had. A lot of people felt they had the right to say and do whatever they liked, no matter who it hurt," Ms Argent said.

"Now with this religious freedom review going on, it's a little continuance of it. They're cowards basically, and feeling a little bit more brave.

"The people who do this are cowards. It's always done at night and sneaky … they wouldn't say it to the person's face, it's like cyberbullying."

Ms Argent also encouraged anyone else who may have received this note or anything similar to speak up and contact police.

"I just think it's horrendous. In this day and age when we do have marriage equality at this moment and this sort of stuff continues … I just keep repeating but it's cowardly," she said.