The widower, who was married to her husband for more than three decades, wanted to take his ashes to Mildura in Victoria's north west as he had wanted.

The woman, who did not want to be named, said it was her husband's 82nd birthday last week and held a ceremony in Mildura, but his ashes were not with her as she had hoped.

Her husband died in February. The warning over executor powers comes as a result of a bitter family dispute.

After the man's death, the woman's step son, who was executor of the will, gave written permission for his father's ashes to be released to his sister, instead of his step-mother.

The grieving wife has not spoken to her step-daughter since her husband's funeral, but said her experience posed a warning to other families to ensure wills were up to date and executors were appointed who would carry out a person's dying wishes.

"I had no idea that an executor of a will could do that," the woman said.

"It's wrong that this can happen, but there's no point worrying about it when I can't do anything about it.

"I've got my memories, but it would've been nice to take his ashes to Mildura and scatter them (in a family garden) as had been his wish."

Commins Hendriks director and solicitor Glen Lollback said an executor's duty was to carry out the terms contained in the will.

He could not comment on the widower's case without seeing the will, but said it was uncommon for it to specifically contain details about what is to occur to the deceased's body.

"The role of the executor, and it is their legal obligation, is to carry out the terms of the will," Mr Lollback said, "Normally it's the executor who organises the funeral and what happens to the ashes, but that doesn't mean the step-mother isn't entitled to them."