The Criminal Bar Association says it can see sense in extending the time limit for charging someone over a death, but it opposes leaving that period open-ended.
Currently, no one can be held criminally responsible if a death happens more than a year and a day after the relevant offence.
Auckland man George Siaosi, who was seriously assaulted in September 2015, died early this year, more than 15 months after the attack.
Criminal Bar Association president Len Andersen said no one should have a charge of murder or manslaughter hanging over their head indefinitely.
"As soon as you have discretion, you have the problem of whether or not somebody should be prosecuted," he said.
"But one of the issues, of course, is that in the days when the rule was first passed, there weren't the medical treatments available now. People can be kept alive a lot longer."
Mr Andersen said it would be useful to look at extending the current cut-off point.
Justice Minister Amy Adams said the issue had not been raised with her before now, and she had asked officials to look into it.
"I think it is worth reviewing the way Section 162 of the Crimes Act works. I've asked my justice officials for advice, and they will report back to me in due course."