Authorities searching for a schoolteacher reported missing two days ago found the body of a white female Wednesday near a busy highway in Long Island, N.Y., and are treating the case as a homicide investigation, police told FOX News.

The discovery along the Long Island Expressway's North Service Road, near Shelter Rock Road, is about 10 miles from where Leah Walsh's car was found abandoned with a flat tire early Monday morning, said Nassau County Police Department spokesman Lt. Kevin Smith.

Police could not confirm whether the body was Walsh's, but said they are investigating the case as a homicide.

The 29-year-old special education teacher was reported missing after failing to arrive at her Glen Cove school on Monday morning.

Her car was later found — coincidentally by her father, a bus driver who happened to be on the highway later Monday morning -- but there was no sign of the woman. Her purse turned up in a ditch nearby.

Earlier Wednesday, rush-hour traffic was stopped for miles along the northbound Seaford-Oyster Bay Expressway in Bethpage as police handed out a "missing persons" flier with a photo of the teacher, as well as a picture of her 2005 Ford Focus. The car was locked near an exit ramp of the highway, with a flat front tire.

Detectives questioned the woman's husband, William Walsh, on Tuesday, but police emphasized it was a routine part of the investigation and noted they had no suspects in the woman's disappearance. He was cooperating with authorities, Smith said.

Leah Walsh, who usually leaves her home for work between 6:15 a.m. and 6:30 a.m., sent a text message to her husband at about 6:25 a.m. Monday, telling him to "have a great day," William Walsh told 1010 WINS radio.

"That's the last I heard from her," he said.

He spoke to reporters later outside the couple's home in Bethpage, before the discovery of the body. "I miss her more than anything," he said.

He described his wife as an "easygoing person" who loved her students. "She wouldn't just leave them," he said. "Something had to have happened."

But Lucas Bean, a friend of Leah Walsh's who lives in Los Angeles, told the New York Daily News that she texted him over the weekend to say that she was in a "huge fight" with her husband and things were not going to work out between them.

The couple have been married for three years; they have no children, police said.

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The Associated Press contributed to this report.