An academic says a police apology has reinstated him as an ethical researcher - but his struggle may not be over yet.

Police policy on access to data is being changed, after a gang researcher went public about being denied information because he knew criminals.

University of Canterbury sociologist Dr Jarrod Gilbert said he's still waiting for the information, but the apology is a step in the right direction.

"What's happened in the last little while has not reflected well on my academic credential. Hence why the apology was so important just to make it absolutely clear that my ethics as a researcher have never been brought into question."

He's concerned police can blacklist academics they don't like, so he'll be waiting to see the fine print of the policy change.

"These contracts have been in place for quite some time but nobody has spoken out before because they were absolutely terrified that if they did they would lose access to that data which is their bread and butter."