The new guidelines, issued by the Vatican's doctrinal watchdog the Congregation for the Doctrine of the Faith (CDF), claims many modern cremation practices increasingly reflect non-Christian ideas about "fusion with Mother Nature".
"In order that every appearance of pantheism, naturalism or nihilism be avoided, it is not permitted to scatter the ashes of the faithful departed in the air, on land, at sea or in some other way, nor may they be preserved in mementos, pieces of jewellery or other objects," the document said.
Olsen said the Catholic Church in New Zealand took its guidelines from the Vatican.
"The bishops will look at the new guidelines that have just come out," she said.
The new rule came from "complex things around our understanding of death and what happens to us in the afterlife and our belief in resurrection".
Olsen said she was "unaware of any specific or direct verses" speaking against scattering ashes.
"I guess it's like a lot of the teaching of the Catholic Church. We interpret the scripture to apply it to a lot of different situations that weren't necessarily specified in the bible. That's a normal process for us, that theological process."
She said the process included applying their understanding to scripture.
When asked whether it was unfair to potentially deny someone a Christian funeral based on an interpretation that was not specified in the bible, Olsen said people still had free will to decide what they wanted to do.
To her understanding, priests would be able to decide for themselves what they wanted to do for "each unique situation".
"That's up to the family and the loved ones and the priest."
She did not know how the guidelines had been received in New Zealand yet as they had only just come out.