A former high-ranking public servant, David Henry, will conduct an inquiry into how confidential information is handled within the Department of Prime Minister and Cabinet.
The department's chief executive, Maarten Wevers, commissioned the review yesterday after one of his supposedly trusted messengers, Michael Ryan, passed a commercially and politically sensitive
Cabinet paper on telecommunications reform to a senior Telecom executive, Peter Garty.
Mr Ryan has been sacked.
Mr Henry is a former Commissioner of Inland Revenue and recently retired as Chief Electoral Officer.
The State Services Commission report on the leak found that the department's systems were properly followed but recommended a review.
Another copy of the Cabinet paper was found behind a photocopier in the office of Communications Minister David Cunliffe.
State Services Commissioner Mark Prebble, who was formerly head of the Department of Prime Minister and Cabinet, appeared before Parliament's commerce select committee on Thursday - Budget day - and answered questions about who knew what and when.
National MPs Gerry Brownlee and Bill English wanted to know whether Prime Minister Helen Clark had known the identity of the leaker before it was officially released at 5pm on Tuesday this week.
But Dr Prebble said "active" steps were taken to keep the name secret as making it public would have jeopardised the investigation, NZPA reported.
The first access Helen Clark would have had to the identity of Mr Ryan was after her adviser Heather Simpson was shown the document after 2pm on Tuesday. But well before then, he had told four managers in the department, who were put in the "very uncomfortable" position of having to keep the secret.
"They all felt, as [department] managers always do, a very strong urge to keep the Prime Minister informed," NZPA reported.
The committee is considering whether to hold its own inquiry into the leak - United Future holds the balance of power on the committee but wants other reviews completed first.
Dr Prebble denied suggestions from United Future MP Gordon Copeland that Mr Garty or Telecom could face action for receiving stolen property.
