Perth family murder. Tributes flood in as police reveal what they know so far...

A mother and her beautiful toddler daughters who were killed inside their own home have been remembered as 'loving and caring.'

Neighbour Richard Fairbrother said the parents, alleged murderer Anthony Robert Harvey, 24, and his partner Mara Harvey, 47, were 'lovely people' and they all looked after each other.

He told Perth Now, 'The way she was with the kids and the way he was with her and the children...just seemed so devoted to the kids especially,' he said. 

'If you had asked me to point to a house in the street and predict this, it would not have been that house.'

His insights come just hours after police said they believe Harvey sat with the bodies of his family for up to six days after the tragic murders. 

Police believe Anthony Harvey murdered his wife aged 47, their daughter Charlotte, 3, and two-year-old twins Alice and Beatrix on September 3 at their Perth home.

They allege that the 24-year-old dad then murdered his mother-in-law Beverley Quinn, 74, the next day on September 4 when she visited the home.

They haven't revealed the cause of their deaths but believe that blunt instruments and knives were used.

Anthony Harvey then drove 1400km to Pannawonica where he told police about the murders.

Officers arrived at the home in Bedford, found the TV on and all the bodies.

The father was then charged with five counts of murder. 

Mara's sister, Taryn, issued a statement yesterday remembering her mum and her sister, and her nieces.

She said her sister 'loved being a mum' and was that her daughters were her world.

'She was so proud of each of them and was doing a great job of raising them. Her girls were her world,' Taryn said.  

'This world is a sadder place with the loss of these five beautiful people but heaven has gained five new angels.'