The England-based commission has, since 1997, considered possible miscarriages of justice in England, Wales and Northern Ireland.
Another commission operates in Scotland, and Norway also has a similar system.
Prof Zellick is a former chairman of the English commission, and, as the New Zealand Law Foundation's Distinguished Visiting Fellow for 2010, is giving a series of lectures throughout the country.
On Wednesday night, he gave a public lecture at the University of Otago on "The investigation of possible miscarriages of justice and the quashing of wrongful convictions".
The commission investigates cases, both major and minor, many having attracted little or no previous publicity, and refers them back to appeal courts where there is a "real possibility" a conviction would not be upheld.
Prof Zellick, who is also a former vice-chancellor of the University of London, noted there was considerable support in New Zealand, including in Criminal Bar circles, for a commission to also be established here.
Adopting this approach had also been debated "for years" in Canada and Australia.
"I simply don't understand why it hasn't been adopted more readily in other countries.
"The experience of both England and Scotland shows that it works and works well," he said.
The commission approach strengthened public confidence in the legal system by identifying cases in which something may have gone wrong, but did not imply any criticism of the overall justice system.
Creating a commission did not generate huge numbers of extra appeals.
The English commission had taken a "pretty hard-headed" approach, and about 96% of applications to it had been unsuccessful, he said.
