
-With AAP.
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A man gassed his entire family to death after his wife discovered he was having an affair with a 17-year-old girl in the Philippines and demanded a divorce, an inquest has heard.
Maria Lutz, 43, Fernando Manrique, 44, and their children Elisa, 11, and Martin, 10, along with the family dog Tequila were found dead in their Sydney home in October 2016.
An inquest today heard the Sydney father was in debt, and there was “little cause for doubt” that Mr Manrique was responsible for the family’s death.
At the opening of the inquest into their deaths at Lidcombe Coroners Court, counsel assisting Adam Casselden said Mr Manrique had planned the murder of his children and wife over some time.

"Maria had no awareness of, or involvement in, Fernando's plans."
The court heard Ms Lutz was a "dedicated, loving mother" to her two severely autistic children.
She was excited about the possibility of going back to work after finding out they would be receiving $50,000 from the National Disability Insurance Scheme, and was set on leaving her cheating husband.
"She was looking forward to life without Fernando," Detective Sergeant Timothy Pooley told the inquest.
Mr Manrique, meanwhile, was in "dire straits" financially, Det Sgt Pooley said.
He owed at least $15,000 to the tax office, had $28,000 in credit card debts and was struggling to pay off the family's two mortgages totalling more than $500,000.