The search for a New York City nurse missing for three months led crews to dig up recently-laid concrete in front of her home, local media reported Monday.

When Mahfuza Rahman missed work for several days in December, worried colleagues called her husband. Mohammad Chowdhury said Rahman had traveled to her native Bangladesh and would return in early March, but Rahman still hasn’t walked through the doors of Bellevue Hospital Center.

Rahman, 30, was officially reported missing by fellow workers on March 4, and on Monday police began scouring Rahman’s Bronx apartment for clues to her disappearance, The New York Post reported. She was last seen leaving Bellevue on Dec. 8.

Detectives “are looking at a second-story back room” where the NYPD’s canine unit reportedly picked up a scent, and authorities have also dug up concrete outside the home, sources told The Post. Police are also interested in several rooms inside the home that were recently painted, a source told The New York Daily News. Officials took a computer tower and several documents from the house as well, CBS New York reported.

Chowdhury is not around to aid the investigation. He and his daughter left the U.S. for Bangladesh, a source told The Post. Travel records confirm that Chowdhury and his daughter were on a flight out of the country, but so far no records of Rahman’s supposed trip to Bangladesh have been uncovered, police told NBC New York.

“On December 15th, he told me, ‘Watch my house, I got to go to my country for two weeks,’” neighbor Jose Garcia told CBS New York. “That’s it. That’s the last time [I saw him].”

Police said foul play is not suspected at this point.

“Right now, it’s a missing person investigation,” a police official told The Daily News. “We don’t have any evidence of foul play. She could have just left.”

Bellevue Hospital has not commented on the investigation.

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