Attorney-General David Parker is being sued by Deputy Prime Minister Winston Peters after his superannuation details were made public in the lead-up to the election last year.
Mr Parker said at Parliament today that "as the Attorney-General, I am the named person who is sued whenever the government is sued, and I'm sued more than a thousand times a year".
"That is the right of Mr Peters to try and find out who it was within government [who] leaked his personal information and used it as a political attack during the election," Mr Parker said.
"I do think you have to protect democracy against skullduggery [... ] It's important that you keep the system clean."
The Attorney-General compared Mr Peters' case to that of journalist Nicky Hager, whose home was raided by police in 2014 following the release of his book Dirty Politics.
This week Mr Hager won a payout and apology from police over the raid.
Mr Peters is suing the Ministry of Social Development, two former government cabinet ministers - National's Paula Bennett and Anne Tolley - and two top civil servants, over the alleged leak of information about him being overpaid his pension.
Mr Peters paid the money back when the matter was brought to his attention.
Mr Parker is sued in place of MSD, in his role as Attorney-General.