A complicated family tree has only added to the mystery surrounding the baffling disappearance of William Tyrrell.
His status as a foster child wasn't even confirmed to the public until three years after he disappeared, and has become the source of much confusion in the years since.
The three-year-old in the Spider-Man suit, who disappeared from his foster grandmother's home in Kendall on the NSW mid north coast, was removed from his biological parents along with his older sister when he was still a baby.
Video taken before he vanished showed him calling his foster dad, who cannot be identified for legal reasons, 'daddy', and the couple refer to themselves as William's mum and dad.
For his biological family, the pain of not knowing what happened to William on the morning of September 12, 2014, has been a constant source of anguish.
His mother, who has two other sons that remain in her care to this day, previously told Daily Mail Australia she 'doesn't want anyone's sympathy'.
Pictured: Who's who is William Tyrrell's complicated family tree - from his wealthy north shore foster parents to a 'homeless' biological dad and single mum raising his two younger brothers
Daily Mail Australia has learned the car which once belonged to William's late foster grandmother was allegedly used by the foster mother near the spot on the NSW mid north coast where he disappeared
William Tyrrell's foster family lead a $141,000 campaign to uncover what exactly happened to their little boy for seven years before the foster mum was identified as a person of interest
Like the rest of the world, she's desperate for the truth about William's disappearance.
On Monday, it was revealed William's foster mother is being investigated as a person of interest. Over the seven years since his disappearance, some 600 people have been considered persons of interest.
New information led to a renewed search of the foster grandmother's home and surrounds where William was last seen. The now-deceased woman's car was seized on Wednesday morning.
Daily Mail Australia understands the Mazda hatchback was allegedly driven by his foster mother on September 12, 2014 - the morning the three-year-old disappeared.
A Supreme Court justice allowed his foster care status to be revealed in August 2017, in what had been an open secret to those who had followed the case for years prior.
'The truth to date has been obscured,' Justice Paul Brereton said.
In light of the new developments in the case, Daily Mail Australia explains who's who in the toddler's life.
A search for William Tyrrell's remains in Kendall will enter its third day on Wednesday
William's biological mother told media she felt like 'the worst mum in the world' after learning her three-year-old had disappeared while in the care of his foster family.
The stay-at-home mum from Sydney's west has two younger sons who remain in her custody, and William's older sister, who is also in foster care.
She previously told Daily Mail Australia she 'doesn't want anyone's sympathy' but has maintained a dignified silence in the wake of William's disappearance.
She occasionally shares photos of her eldest son online and maintains a private Facebook group dedicated to bringing him home.
Meanwhile, William's biological father - who is no longer dating his mother - allegedly spiralled after the toddler went missing.
He developed a drug habit and has been in and out of jail. Some relatives have described him as a 'career criminal' in the past.
It's understood he is homeless after his last stint in jail.
William's biological mother told media she felt like 'the worst mum in the world' after learning her three-year-old had disappeared while in the care of his foster family
William's biological father - who is understood to no longer be dating his mother - allegedly spiralled after the toddler went missing
William's biological paternal grandmother has long been the face of his family, making public pleas for information that would lead to his safe return
William's biological paternal grandmother has long been the face of his family, making public pleas for information that would lead to his safe return.
On Wednesday, she told The Daily Telegraph of the toll the tragedy has had on herself and her family.
Her son, William's father, has been in and out of jail, is estranged from his family and suffers from mental illness.
'He's homeless,' she said. 'I don't know where he is. I heard from him once when he got out, I felt so bad because he had nothing.'
The woman, who cannot be named for legal reasons, said her son was desperately trying to get a medical script for prescription drugs.
He'd told a chemist 'I need them (pills) because I lost my son seven years ago', and reportedly began to cry.
'He's never opened up about that... Look what they've done to me, look what they've done to my son,' his mother said.
FOSTER PARENTSWilliam's foster parents have never been formally identified, but have given anonymous interviews and maintained a $141,000 campaign to find their boy.
Police this week confirmed they'd received new information which led to the reinvigorated search, and William's foster mother has been singled out as a person of interest.
The foster mother, now 56, was at the home with her own mother with William and his sister when the boy is believed to have disappeared. Her husband was in town.
The couple are wealthy professionals from Sydney's north shore and had the Tyrrell children in their custody for about two years before the tragedy.
William Tyrell's foster mother - the main person of interest in the three-year-old's disappearance - has appeared in public as police step up their search for the missing toddler. She walked out of her home on Sydney's upper north shore on Wednesday morning wearing a pair of slippers before spotting media crews
In early September, a leak from a NSW Police source revealed cops had zeroed in on a suspect which prompted William's foster family to issue a scathing statement downplaying the claims (pictured, William's foster mother who wept while giving evidence about the boy's disappearance at an inquest in 2019)
In the years since William disappeared, the couple have spearheaded the official 'Where's William' campaign and made regular pleas for his safe return.
In early September, a leak from a NSW Police source revealed cops had zeroed in on a suspect which prompted William's foster family to issue a scathing statement downplaying the claims.
'Imagine waking up to an unsubstantiated article published by a large media outlet claiming a 'senior officer' within NSW Police shared that they have a NEW person of interest, whilst inferring that this heinous crime is on the brink of being solved,' they said in a statement shared to their 'Where's William' website.
'Once again we are forced to watch others objectify William for personal gain... fake news causes more heartache for William's loved ones.'
William's foster parents have both vehemently denied any involvement in his disappearance.
