OCONOMOWOC, Wis. (AP) _ A tip from a company that sells explosives led investigators to a house containing bombs, a keg of gunpowder, tear gas grenades and other explosive devices, authorities said.

A 25-year-old man who posed as a policeman while purchasing riot gear was taken into custody Saturday, Waukesha County deputy sheriff Thomas Lentz said.

''I'm not well-versed in explosives but there is no question there was enough stuff in there to blow up the house and who knows what else,'' Lentz said.

The man's identity was not released in the absence of formal charges. He was sleeping when deputies arrived with a search warrant. Neighbors said the man told them he worked as a security consultant.

Deputies found a loaded .38-caliber pistol under the man's pillow, a .45- caliber automatic pistol, 20 homemade bombs of various size, 10 tear gas grenades, detonators and other devices, Lentz said.