A Sydney father was in financial strife and having an affair with a teenager in the Philippines when he killed himself and his family, an inquest has been told.
Fernando Manrique, 44 and his wife Maria Lutz, 43, were about to divorce when they were found dead along with their children Elisa, 11, and Martin, 10, and the family dog Tequila, in their northern Sydney home in October 2016.
They all died from carbon monoxide poisoning.
At the opening of an inquest into their deaths at Lidcombe Coroners Court, counsel assisting Adam Casselden said there was "little cause for doubt" that Mr Manrique was responsible.
"He had planned the deaths of his family over the course of some time," Mr Casselden said on Monday.
"Maria had no awareness of, or involvement in, Fernando's plans."
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.
The family trust account, meanwhile, had just $6 in it.
Despite his debts, Mr Manrique was also supporting a woman he was in a "serious relationship" with in the Philippines, where he travelled for work each month.
The woman, known only as Jamilyn, was 17 when she met Mr Manrique in 2015 at a bar where she worked.
He told her to quit her job and that he would buy her a house.
Ms Lutz, meanwhile, had asked for a divorce.
Police say Ms Lutz was excited about going back to work after finding out she would be getting $25,000 in support through the NDIS for their children, aged 11 and 10.
"She was looking forward to life without Fernando," Detective Sergeant Timothy Pooley said.
Carbon monoxide
Mr Manrique purchased two cylinders of carbon monoxide 10 days before the family's deaths and arranged for them to be delivered to his friend Jairo Campos' house.
He also made four visits to Bunnings in as many days, buying more equipment for his plan.
Mr Campos told the coroner his friend told him he needed the cylinders to run tests on "gas released by cars in underground car parks".
Mr Manrique paid him $400 for storing the cylinders.
Mr Casselden said it appeared Mr Manrique intended to die with his family, although they could not be certain.
He said the inquest would be looking into supply, delivery and storage of carbon monoxide.
"A real concern is the relative ease with which Fernando was able to source the carbon monoxide," he said.
The inquest continues before deputy state coroner Elaine Truscott.
Lifeline 13 11 14
beyondblue 1300 22 4636
