Police dug up the basement of a Queens, N.Y., plumbing-supply store yesterday in search of the body of a Baruch College student who vanished 12 years ago while she was five months pregnant with her married professor's child, sources said, according to The New York Post.

Aided by a cadaver-sniffing dog, the NYPD cold-case squad believes that the dig at the Jamaica shop will yield the remains of Kristina Kupka, a 28-year-old undergrad who vanished in 1998.

Kupka's lover and chemistry instructor at the time, Darshanad Persaud, was a prime suspect in her disappearance, but without evidence he was never arrested.

"No comment, I can't help you out," Persaud, 41, a Guyanese immigrant who is now a dentist in Tampa, Fla., told The Post.

The cadaver-sniffing dog indicated there were human remains in the basement of the Liberty Avenue shop and investigators noticed one section of the concrete floor did not match the rest.

Teams dug down six feet and are expected to resume the search today.