The Police Minister is rejecting calls for an inquiry into online gun sales.

Labour MP Stuart Nash has today called on TradeMe to temporarily halt the sale of weapons, amid revelations Whangarei double murderer Quinn Patterson bought firearms online.

Deputy Prime Minister Paula Bennett believes it's a knee jerk reaction from the Opposition.

She said the police should be left to carry out their investigations.

"We don't know when these guns were purchased, we don't know how. If there is a loophole then we are completely open to closing that."

Mr Nash argues the Government should launch an independent inquiry into online sales.

He called on TradeMe to to suspend sales of firearms online "until we've had a chance to take a good look at this and tighten up the rules."

However, Ms Bennett think it's too early to jump to conclusions, but believes there are questions to be asked.

"I just think the calls from Labour are them barking at every car - Police are investigating how this guy has got hold of guns, so I think there are unanswered questions."

A former police negotiator told Heather du Plessis-Allen this morning that he's surprised at how easily Quinn Patterson gained access to firearms, considering he did not have a gun license.

Retired police officer Lance Burdett lead negotiations with gunman Jan Molenaar, during the Napier Siege.

"That surprises me," he said.

"I sit on the fence with this as to whether firearms should or should not be available. Should we license firearms or people, or should we do both?"