A relative of an admitted terrorist who hoped to detonate explosives in New York City’s subways recalled yesterday how he stumbled upon his nephew’s suicide-bomb making operation in a suburban Colorado house.

Najib Jaji told a Brooklyn federal jury he discovered Najibullah Zazi working with “an icebox full of bleach, a mask, goggles and a scale . . . nail polish . . . and a clear liquid.”

The testimony came during a trial for Zazi’s father, Mohammed Zazi, who allegedly misled federal agents in September 2009.