Police say one of three men who were allegedly plotting a dramatic robbery blew the cover of the operation Monday when he told investigators about the plot.

They say Juneal Ali and two others planned to use a fake bomb while dressed in traditional Muslim attire to rob a check-cashing store on the 15th anniversary of the Sept. 11, 2001 terror attacks Sunday.

One of the three talked the group out of actually committing the robbery, according to police. They say he was concerned that there were too many people around and postponed the heist until Tuesday.

But on Monday, police say one of the plotters walked into the 42nd Precinct and told investigators the whole story.

Police say they then arrested Ali, who was on his way to pick up the man who turned him in. In his car, they say they found dark robes, an imitation pistol and road flares tied together with other props to look like an explosive device.

Police say Ali told them that it was he who was on his way to tell his co-conspirator that he wanted to call off the robbery.

But investigators charged him with conspiracy to commit robbery and attempted robbery. It's unclear what charges the other men may face.