A legal expert sees a reasonable chance New Zealand could waive diplomatic immunity after allegations about an Australian diplomat's partner surfaced.

Sky News has reported the partner was involved in an altercation in central Wellington early on Sunday.

New Zealand Police have confirmed they're seeking to waive diplomatic immunity for an individual, so charges can be laid.

Electoral law expert Graeme Edgeler says such actions tend to be on a step by step basis.

"The friendlier we are with those countries, the more likely it is that they might agree."

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