Western Australia's consumer watchdog is urging more women to come forward after claims an operator in the state's south-west has handed out fake ultrasound photos of unborn babies.

Consumer Protection is investigating a number of complaints from women in Bunbury who claim the foetal ultrasound pictures they were given were generic photos found online.

The complaints relate to a business which is operating out of a private residence in Bunbury.

It is understood a number of women realised what had happened when they posted photos of their scans on Facebook.

Bunbury resident Catherine Osment became suspicious when the photographs she was given were very different from what could be seen on her live ultrasound and DVD.

She said all the serial numbers and names on the back of the photo prints were completely different.

She posted her concerns on a Facebook page asking if any other women had the same concerns.

As other women responded by posting their images, it became clear that many of them had received the same images.

"I felt upset, for other people, not just me," Ms Osment said.

"People who've had these photos for years and up on walls and shared photos with families... all thinking that it's their grandchildren, nieces, nephews, and it's not.

"It's of babies that we don't even know where they originate from."

Ms Osment said she just felt lucky that, as she is still pregnant, she still has time to get new ultrasound imaging done.

Consumer Protection's David Hillyard says anybody concerned should refrain from comments on social media and instead make formal complaints to the Department of Commerce.

"If people have got concerns about receiving goods and services again they should come to us with a complaint," he said.

"But it's certainly, like we said, very early days and we need an opportunity to assess what these complaints are about and have a chat to the business concerned.

"What we would suggest to these people is rather than going into those environments [social media] and talking in general terms about it, perhaps they should lodge a complaint with us, allow us to look into those matters and if they're entitled to further actions then certainly we will assist them in those steps."

'I was getting excited over someone else's baby'

Bunbury resident Shicara Linnett had her daughter Allira about a year ago.

She says she had been excited to see the 3D and 4D imaging.

"I was like 'Oh my god, you can see your baby!', so I booked an appointment," she said.

Ms Linnett said she had no idea the images might not have been of her daughter.

Yesterday, after being alerted to the possibility that her photographs may not be legitimate, she uploaded the images she had to the Facebook page to see if anyone else's matched them.

She says there was a response within minutes.

"Heaps of people had said already [that they had] probably about three of my photos," she said.

"I've got a few of the same photos as [my friend] does, but she had her baby probably six months before I had mine.

"So I soon discovered that many people have the same photos as I do, so it's pretty upsetting."

Ms Linnett said it was disappointing to find out that during the time between the scan and giving birth, she was looking at images of a child that was not hers.

"I was looking at someone else's baby and getting excited over someone else's baby."