Nicole Marie Beecroft made a new friend in the Washington County jail last winter, but relations went sour after Beecroft revealed details of her baby’s death that happened six years ago, a witness ­testified Wednesday in court.

Emily Frye said she spent two months in a cell next to Beecroft’s, and they ate meals together and “talked a lot about problems we have in the outside world.” They were known to each other as “Nikki” and “French Frye.”

Their friendship fell apart after fellow inmates in their housing pod taunted Beecroft as a “babykiller” and Beecroft spread jailhouse gossip that Frye was a “snitch” and couldn’t be trusted, Frye said.

Frye, of Oakdale, was being held on felony charges of third-degree murder in connection with the methadone overdose death of a Scandia man in January. Beecroft, also of Oakdale, already had spent six years in prison for killing her newborn baby, and had been moved to the county jail in Stillwater to await her new trial on an indictment of first-degree premeditated murder.

Last summer, the Minnesota Supreme Court ordered a new trial for Beecroft on grounds of interference by people not associated with the first trial.

Frye, now on furlough from the jail for treatment at a drug addiction center, testified in Washington County District Court that she voluntarily met with a police investigator this month to state her concern about Beecroft’s baby. When prosecutor Karin McCarthy asked Frye why she came to court to testify, she responded: “I’m doing it for the baby. It just breaks my heart.”

Frye said Beecroft talked of the case nearly every day but showed little emotion about it. Beecroft confided that she drank alcohol in hopes of ending the pregnancy, Frye said, and described disposing of the girl’s body in a trash can soon after giving birth in April 2007.

Beecroft is accused of stabbing her baby 135 times, but her defense attorneys contend the baby was already dead when the stabbing occurred.

“I believe she might have thought it was alive,” Frye said at one point but in another reference recalled that Beecroft told her “the baby was gray and not moving, not breathing.”

Defense attorney Luke Stellpflug, implying collusion, tried to discredit Frye’s statements to police as being identical to that of another female jail inmate. He also asked Frye why she said Beecroft had been held in segregation, suggesting serious misbehavior, when in fact she had been locked in her cell for a day for having too many religious books.

In response to his questioning about the timing of her decision to testify, Frye said she decided to testify to change her “negative ways” and denied fabricating her testimony.

“Did you make this up? McCarthy asked. “No,” Frye said in a strong voice.

Beecroft’s trial is scheduled to continue into next week.