Robyn Fendall has been suspended by the Legal Services Agency this week for allegedly overbilling as a supervising duty lawyer at the Waitakere District Court in West Auckland.
A Legal Services Agency spokeswoman declined to comment on the reason, as the barrister had appealed the decision.
A panel would examine the evidence and review her appeal.
The spokeswoman declined to say whether the decision to suspend Ms Fendall from the legal aid list was temporary or permanent.
Publicly-listed figures show Ms Fendall has received more than $1 million of legal aid in the past three financial years, including $572,000 in the 2006-07 financial year.
Ms Fendall declined to comment.
"I'd need to talk to my lawyer first... Why don't you ring my lawyer and she can fill you in?"
Her lawyer, Maria Dew, did not return messages.
The ban comes after weeks of debate about the growing legal aid bill and calls for reform in how the justice system is funded.
Dame Margaret Bazley is carrying out a review of legal aid for Justice Minister Simon Power, after the taxpayer-funded bill ballooned from $84 million five years ago to an estimated record $144 million next year.
Almost $20 million more was spent last year in administration costs.
Dame Margaret recently released a discussion document which said legal aid in criminal courts, particularly in Auckland, was characterised by "inefficiencies and poor service".
She accused some legal aid lawyers of turning up for court unprepared, overcommitting themselves with cases and seeking unnecessary adjournments.
A small but significant group was described as "car-boot lawyers", paid between $105 and $182 an hour, who saved on overhead costs by having no office.
Dame Margaret listed complaints about lawyers turning up to court without having done basic preparation, such as reading the prosecution's brief or even having spoken to their clients.
Lawyers were also over-committing themselves and failing to turn up because they were at another case.
Dame Margaret said there were low barriers to entry to become a legal aid lawyer and there was no real monitoring of performance.
Attorney-general Chris Finlayson has also criticised the standard of many criminal lawyers.
He described some as incompetent and suggested financial penalties for those who wasted the court's time.
Criminal Bar Association president Anthony Rogers said last week it was regrettable Dame Margaret's discussion paper did not sufficiently acknowledge the "utter dedication and professionalism" shown by most lawyers.
"Far from clipping the ticket to gain payment for unnecessary court appearances, most lawyers assiduously avoid additional appearances. They are simply too busy to play such games," Mr Rogers said.
