"We want to make it clear — they are not suspects in this investigation. They have been helping us."
Wilde also revealed Cleo's biological father had been ruled out as a suspect, saying he was "nowhere near the area" when she went missing.
It comes after police searched Smith andGliddon's house for a third time on Wednesday, saying it was "standard practice" as part of eliminating everyone who was at the Blowholes Campground in Macleod on October 16 as a suspect.
"We must do a thorough investigation," Acting WA Police Commissioner Col Blanch told 6PR radio.
"The parents have been nothing but helpful. We've worked very closely with them; they've let us into their home, they've let us into their cars, their phones – everything.
"Our job is to eliminate everyone that was at that campsite, and that is a systematic and thorough approach in doing so in any investigation. That really is the focus of the investigation at the moment."
Cleo was last seen in the early hours of Saturday, October 16 where her family was camping at the Blowholes beachside campground in Western Australia's Gascoyne region.
Smith said Cleo woke up at 1.30am asking for water before going back to bed. Her mum woke up at about 6am to find the tent unzipped and Cleo missing. The police were called just before 6.30am.
Police quickly ruled out the possibility the 4-year-old could have wandered out of the tent on her own, saying the zipper on the tent was up so high there was no way she could have opened it by herself.
A major focus of the police investigation now revolves around a report from two people who said they saw a car turn right off Blowholes Rd onto North West Coastal Highway, heading towards Carnarvon, between 3am and 3.30am on the day Cleo vanished.
A $1 million reward has been offered for information that leads to the girl being found.
Sick online trolls target Cleo's parents
The majority of comments that have been left on Smith's Facebook page have been messages of hope and support.
Unfortunately, it is a different story for Gliddon's page, which has become a hotbed for trolls to voice their vile accusations against the couple.
Despite other users reporting the comments, many of them have remained on the page, with some now a week old.
One commenter said the couple should be subject to a polygraph test to "clear your names", while others accused them of withholding information from the police.
Another person accused the couple of not looking sad enough during media appearances.
Some of the more sickening comments suggest Gliddon and Smith may have intentionally harmed Cleo.
A family friend, who did not wish to be named, branded the comments an "utter disgrace".
"Most of the Facebook comments are being made by parents themselves and I think that's disgusting," he told Perth Now.
"Just imagine if it happened to them and they had to read all these horrible comments during undoubtedly the hardest time of their lives.
"The police have cleared Jake and Ellie from being suspects. I have known them for years and I can tell you they are the best people I know and my heart aches for them."
He told the publication that the people "sitting behind their keyboards" should just leave the family alone, adding there was "no right way to act when your child is stolen from you".
Search for mystery driver continues
The Blowholes is in such a remote part of the country that there is only one sealed road into the area, which comes off the North West Coastal Highway and ends at the campsite.
Police are searching for a car that was spotted in the darkness by two men – apparently heading to work – and have appealed for the driver to come forward.
It was seen turning right off Blowholes Rd onto North West Coastal Hwy, heading towards Carnarvon, between 3am and 3.30am the day Cleo disappeared. The description given was of a passenger vehicle, such as a sedan or wagon.
Police have repeatedly indicated the person may not be a suspect but may have relevant information. It's been a week since the appeal and no one has come forward.
CCTV footage from a Rio Tinto mine site and nutrition business along the Blowholes Road have given no more clues about the car and who was in it.
Disturbingly, there are a number of dirt roads and trails where someone could disappear without being seen and police have indicated they are looking into them.
A back way out of the campsite is also being investigated by police.
Despite collecting CCTV from across the state there have been no solid leads for police.
Wilde confirmed on Friday that police did not have any suspects "at this stage" in the mysterious case.
– with NCA NewsWire
