The stepmother of a four-year-old girl allegedly left to die in her cot has been arrested on suspicion of murder.
Willow Dunn’s body was found malnourished and decomposing in her bed at her home in Brisbane last Monday, her face partially eaten by rats.
Her father, Mark James Dunn, 43, was charged with murder after he allegedly found the toddler dead two days earlier and didn’t call emergency services.
Dunn’s partner Shannon White was on Wednesday arrested and is expected to also be charged with murder.
Willow Dunn’s (pictured) body was found decomposing in her bed and police revealed she died of malnourishment and sustained neglect
Shannon White (pictured) is Willow’s stepmother and was best friends with Willow’s biological mother Naomi Dunn for 20 years before moving in with Mr Dunn after she died
She allegedly told police last week that caring for Willow, who had Down syndrome, was not her responsibility as she was not her biological daughter.
This was despite writing ‘I would do anything for my kids’ on her Facebook in 2014.
Ms White’s daughter, Taliah, 19, would sometimes feed and bathe Willow after moving in to the house along with her mother.
The teenager has not been arrested and has a sister of a similar age who still lives in Adelaide.
But for the past year the toddler is believed to have been solely in the care of her father, who allegedly left her in squalor.
Dunn allegedly left the helpless little girl lying in her bed, starving to death, long enough for her to have infected sores on her hips down to the bone.
Willow’s body was found malnourished and decomposing in her bed at her home in Brisbane last Monday, her face partially eaten by rats, and her father Mark James Dunn (pictured) charged with murder
Police confirmed a post-mortem revealed the toddler died of malnourishment and sustained neglect.
Willow’s mother Naomi Dunn died on November 5, 2015, from complications following Willow’s birth about a week earlier.
Her death sent Dunn into a tailspin that left him depressed and struggling to cope.
Daily Mail Australia understands Willow was sent to live with an aunt and uncle after her mother’s death.
Their father up to a year later took her and her brother, who is now seven, back to live with him despite a custody attempt by the relatives.
Dunn allegedly told police after his arrest he couldn’t handle his daughter’s condition and was depressed about his wife’s death.
Willow, who suffered from Down Syndrome, and her brother who is now seven (right) was sent to live with an aunt and uncle after her mother’s death
Naomi Dunn died on November 5, 2015, after giving birth to her daughter Willow, devastating her family
A Facebook post from Ms White in 2014 claimed Ms Dunn was her best friend of 19 years (pictured)
Ms White, who was Ms Dunn’s best friend and a bridesmaid at her wedding in 2014, later started dating Dunn and moved from Adelaide to live with him.
‘I still have my bestie from 19 years ago Naomi Kipping (Ms Dunn). She’s always been there for me no matter what,’ Ms White posted on Facebook in 2014.
Ms Dunn replied: ‘Awwww love ya xx.’
The two regularly commented on each other’s Facebook posts and that of Ms Dunn’s adult children from an earlier relationship.
Ms Dunn once wrote Ms White was ‘so dam (sic) hot’ in a photo, to which she replied ‘oh baby thanks xx miss u’.
Ms Dunn’s adult son mourned his half-sister on Facebook in the days after her death, and later shared a post condemning Ms White.
‘Rest in Peace Willow. It’s so heartbreaking things have turned out this way, but you will forever be in our hearts. Fly high with mum,’ her son wrote.
Dunn’s family have since accused him of pushing them away so he could pursue a relationship with his dead wife’s bridesmaid.
A teddy bear wearing a Parramatta Eels jersey is seen in the bedroom of the Cannon Hill home on Tuesday (pictured) just hours after little Willow was allegedly found in her cot
A stroller was seen in the front yard on Tuesday (pictured) as police continued to investigate what happened to the toddler
He allegedly banned his wife’s other children from seeing Willow, blocking their phone numbers and social media accounts.
‘He pushed away everyone when (Naomi) died so he could be with Shannon,’ the relative told the The Australian.
Detectives are investigating whether Willow spent the entirety of her four years on earth in squalor without adequate food or care.
She was allegedly badly malnourished, and had bone-deep sores on her hips when she was found.
Willow was not Down syndrome registered with the NDIS, leading detectives to allege she was not receiving the care she needed.
Dunn allegedly told police he noticed Willow’s deteriorating condition and should have sought help before her death.