A Queensland Police statement released yesterday said Scott Maitland, 35, and his partner Cindy Masonwells, 33, were last seen in Cairns collecting their newly restored Holden panel van from a Bungalow workshop on July 5.

On Thursday afternoon Detective Senior Sergeant Ed Kinbacher said police investigations were currently focused on third party involvement.

Mr Maitland's former partner Donna Astill said she was scared and worried for the father of her daughter, Ryhane Maitland.

"I'm only getting bits and pieces of information from the police and Scott's parents," Ms Astill told The North West Star from Wodonga on Thursday afternoon.

"The last thing I heard from the police was that they haven't had any access to bank accounts and no phone contact."

Ms Astill said she first discovered the couple were missing after returning from a holiday with her sister earlier this week.

"I got a call from Scott's mum on Tuesday afternoon to check if I'd heard from them and then on Wednesday she called and was quite panicky and I said to ring his work and try the police.

"We're just hoping they've broken down somewhere and with the wet weather have had difficulties getting reception, that's what I'm praying for, especially for my daughter."

She said Ryhane was in shock about her father's disappearance.

"She just said before, 'my head understands it but my heart doesn't'," Ms Astill said.

"You hear stories about wicked step mothers but Cindy is fantastic, they both have a lot of contact with Ryhane.

"This is really out of character for them, especially to leave Ryhane, who is their first baby, and their dogs, which are their second babies."

Mr Maitland and Ms Masonwells had travelled to Cairns for an engagement party but never made it to the celebration, she said.

"If they say they're going to a party, then they go, this is really strange."

Ms Astill described her ex as a funny, caring and honest guy, saying he worked for Xstrata at the mines.

"He's your average Joe type of person, very humble and would help anyone if they needed it," she said.

"He's a brilliant person, so is Cindy, she's gorgeous.

"His parents are frantic, they're such beautiful people."

She said the couple were last seen leaving a car workshop in a green, 1975 Holden Sandman panel van.

On a Facebook page created yesterday for the couple, Ms Astill said the Scott was approximately 198 centimetres tall with a slim build, dark brown hair and a distinctive deep voice.

Cindy is approximately 167 cm tall, with a medium/slim build and light brown, medium tolong hair.

The Facebook page, called "Please help us find my daughter's dad and step-mum", already had 956 'friends' at 4pm Thursday afternoon.

Concerned friends left messages of support for the family.

Tiffany Richards said "give Marge and Waine hugs from us, hopefully there [sic] found safe and sound!".

Jenelle Dillon said "I know this couple, I have just heard it on the radio and can I say I am shattered".

Anyone with information can contact Crime Stoppers on 1800 333 000.