Mr Power retired from politics in November, and Ms Collins discussed the commission vacancy with Dr Mapp some time before December 20, when Dr Mapp emailed Ms Collins his CV.
In January, Ms Collins decided on Dr Mapp and declined to check the availability of the people that Sir Grant had put forward.
The released documents do not reveal the names of the six people, citing privacy reasons.
A cabinet paper in February showed that Ms Collins did not consult or inform any departments, agencies or interest groups.
She consulted Attorney-General Chris Finlayson, the Government caucus and Act, Maori and United Future parties.
Labour leader David Shearer said the appointment needed scrutiny.
"The perception is that there have been a number of appointments made that have been close to National.
"These types of appointments might just fuel that perception - that National is looking after their own."