The streets surrounding the house were cordoned off, leaving many residents unable to return home.
Neighbour Cassie Latemore said that at about 12.45pm an armed officer knocked on her door and told her to put her dog inside, close all her windows and stay indoors.
About an hour later, she saw officers putting on gas masks and at least one gas grenade being prepared.
She said there were about 10 armed officers surrounding McLean's house, some on her property.
"I have got front row seats to this," she told the Rotorua Daily Post as the incident unfolded. "I'm a bit nervous actually."
At 2.10pm, more than 20 loud bangs rang out, believed to be gas grenades.
Meanwhile, associates and family of McLean began arriving at the cordons asking police to be let through. One told the Rotorua Daily Post the incident could have been avoided if they had been called earlier to speak to McLean.
"I could go down there now and get him out," he said.
The officers then re-grouped outside the house and donned protective gear before they ran back and entered the house. Two flash bangs were heard, followed by silence.
Miss Latemore said she saw officers searching in, around and even under the house, to no avail. She said McLean had lived in the house for about three weeks and was a "nice guy".
Anyone with information on McLean's whereabouts should call Senior Sergeant Graeme Hill of the Tokoroa police on (07) 885 0109.