The suspect -- a 31-year-old woman whose name was not reported -- has implicated herself the death of Sunando Sen, 46, the New York Daily News said.
Sen was killed at an elevated station in Sunnyside, Queens, where witnesses said a woman who appeared to be in her 20's pushed him onto the tracks.
The newspaper said police received tips after releasing surveillance video images and a sketch of the woman witnesses described. Police also posted a $12,000 reward for information.
Sen -- an Indian immigrant who had lived in the city for 20 years, was a graphic designer and an owner of New Amsterdam Printing Co.
He appears to have been a random victim. Others waiting on the subway platform said the woman, described as heavyset and of Hispanic appearance, had been talking to herself as she walked the platform, then sat on a bench, got up again, followed Sen along the platform and shoved him to the tracks as a train approached.
By the time the train halted, his body was under the second car.
Another Queens man was killed at a subway station when he was shoved in front of a train Dec. 3 in Manhattan. A homeless man has been charged with murder in that case.