Catholics have been told that while cremation remains okay, the ashes of loved ones must be stored in a "sacred place" - not scattered, stored on a mantle or divided between family members.
The Vatican revealed on Tuesday that it had instigated new guidelines on what to do with dead bodies, due to concerns that the current practice of cremation promotes "erroneous ideas about death".
It says those ideas include pantheism, a doctrine that equates God with the universe and everything in it, naturalism, a belief that there are no supernatural forces, and nihilism, the idea that life is meaningless.
"Following the most ancient Christian tradition, the Church insistently recommends that the bodies of the deceased be buried in cemeteries or other sacred places," it says.
The Vatican says the new guidelines have been put in place in response to the growing popularity of cremation across the world, and in an attempt to "set out norms" that make clear the "preference of the burial of the remains of the faithful".
The Cremation Association of North America says that in the last 15 years, the number of people being cremated has doubled to encompass almost 50 percent of the US population.
In the set of new guidelines, the Vatican makes clear that "mementos, pieces of jewellery or other objects" are also not permitted as containers to store ashes.
"The church continues to prefer the practice of burying the bodies of the deceased, because this shows a greater esteem towards the deceased," the Vatican's guidelines state.
"Nevertheless, cremation is not prohibited, unless it was chosen for reasons contrary to Christian doctrine."
The guidelines move on to explain why cremation is still allowed despite the changes to what is permitted afterwards.
"The Church raises no doctrinal objections to this practice, since cremation of the deceased's body does not affect his or her soul, nor does it prevent God, in his omnipotence, from raising up the deceased body to new life.