Prime Minister Bill English says the government's not keen on a wholesale ban on online gun sales following a double shooting in rural Whangarei.
Quinn Patterson, 55, last week shot and killed Wendy Campbell, 60, and her daughter, Natanya, 37, while they were conducting a property inspection of the home he was renting.
The house Patterson was in went up in flames during a subsequent shoot-out with police, his body found in the rubble days later.
Auction website Trade Me over the weekend confirmed Patterson had traded guns online, and reports suggest he used someone else's firearms licence number.
Patterson did not have a licence himself, as required for online gun trading.
Mr English on Monday told TVNZ 1's Breakfast procedures around online gun buying had already been tightened up in the past few years and said an outright ban on online sales would be too far.
"The internet is part of doing business these days. And it may even be counter-productive to jump to a position of saying 'There's no internet trading of firearms'," he said.
"Because there's a very large, legitimate, controlled and responsible trade ... We are very unlikely to go that far."
He said while the government was keeping an open mind about possible law changes to fix loopholes, the facts of the case had yet to be established and any new rules needed to be balanced with the effect on legitimate gun owners.