The four members of the Lutz-Manrique family, who died in a murder-suicide in their Sydney northern beaches home a fortnight ago, have been farewelled at a funeral.

Maria Claudia Lutz, 43, Fernando Manrique, 44, and their children Elisa, 11, and Martin, 10, were found dead in their Davidson home from what police said was deliberate gas poisoning.

Their bodies were found when police forced entry to the home after being alerted by a concerned friend.

Elisa and Martin both had significant disabilities, including autism, and attended St Lucy’s School for children with disabilities at Wahroonga on Sydney’s upper north shore.

Today, members of the school community joined with the relatives of the family to mourn them at a requiem mass at the Holy Name Catholic Church at Wahroonga.

Members of both the Lutz and Manrique families have travelled to Sydney from Colombia to attend the funeral.

“Our family is now gone and with the Lord,” they said in a statement.

“They found peace.

“It is for us that remain to seek the fortitude and acceptance that may bring peace to our hearts.”

In keeping with the wishes of their families, Ms Lutz, Mr Manrique, Elisa and Martin were farewelled together.

Maria Claudia Lutz and her children Elisa and Martin were found dead in their Sydney home. Photo: Facebook

Exposure may result in awareness: family

The mass was told the Lutz and Manrique families were united in their grief, and they made no judgement about the circumstances in which their loved ones died.

“We must now find peace and acceptance in our hearts,” relatives said in a statement.

“It is not easy and the exposure has only exacerbated our pain.

“[But] perhaps this same exposure may result in awareness of the enormous economic, social and psychological stresses that families of children with disabilities bear.

“Whilst science works day after day to comprehend all these different conditions, society cannot remain indifferent to the situations families bear, and needs to move and develop means to support them better.

“Through all of this, for the families that love and care for their disabled children, every minute is special.

Disability didn’t cause deaths, says school principal

The Acting Principal of St Lucy’s, Warren Hopley, commended relatives of Ms Lutz and Mr Manrique for supporting each other in the wake of the tragedy.

The order of service for the Lutz-Manrique family. Photo: AAP

“They understand that Dad [Mr Manrique] must have had a problem here and for nobody’s fault he has snapped,” Mr Hopley said.

“Because he was a father who loved his children, there is no doubt about that.”

“So both families understand the problem and have really bonded together very closely over this.”

Mr Hopley said while the reason Mr Manrique took his family’s lives may never be known, his children’s disabilities were not the trigger.

“These deaths haven’t been caused by disability,” he said.

“But families do need a great deal of support when it comes to their children with intellectual disabilities.

“Many lose lots of sleep, every minute of every day — it’s lots of work looking after kids like this.

“But they’re also beautiful children, with unique personalities like all of us, so as a society we need to understand and be better educated about the great wonders of these children.”

Ms Lutz, Mr Manrique, Elisa, and Martin will be cremated in a private service and their remains will be returned to Colombia.

– ABC