Rare Australian conjoined twins Faith and Hope have died with their parents at their side.

The girls, who were almost three weeks old, were with their parents Simon Howie and Renee Young at the Westmead Children’s Hospital in Sydney.

A hospital spokeswoman said they died just after noon (AEST) on Tuesday.

Faith and Hope Howie, who had an extremely rare condition called diprosopus, shared a body, limbs and a skull, but each had their own brains and a set of identical facial features.

There are about 35 similar cases recorded worldwide and none of these babies survived.

Doctors discovered the babies’ condition during a routine ultrasound at 19 weeks and their parents went against medical advice when they continued with the pregnancy.

They were born at 32 weeks by emergency caesarean on May 8.

Both parents, who already have seven children, showed enormous pride in their twins.

“I think they’re beautiful, Simon thinks they’re beautiful, really that’s all that matters,” Ms Young told The Nine Network after the birth of the girls.