MOSCOW, Idaho — The FBI has joined the investigation into the gruesome stabbing murders of four University of Idaho students — as prosecutors warn that the killer, or killers, are still at large.

Moscow Police Chief James Fry said the FBI has joined the Latah County Sheriff’s Office and the Idaho State Police to investigate the bloody murders, which happened at the students’ off-campus home.

“Currently, we have 25-plus investigators working this case,” Fry said. 

The murderer is “still out here,” Fry added, noting that “investigators are continuing to collect evidence at the scene.”

Meanwhile, Latah County Prosecuting Attorney Bill Thompson said, “It certainly is possible” there is more than one suspect on the “Today” show Thursday.

The four victims just hours before their deaths.kayleegoncalves/Instagram

The murders of Ethan Chapin, 20, Madison Mogen, 21, Xana Kernodle, 20, and Kaylee Goncalves, 21, on Sunday rocked the school community, with police describing the crime scene as the “worst they’ve ever seen.”

All four of the victims are said to have been stabbed to death in the early hours of the morning while their two roommates were upstairs.

Authorities revealed Wednesday a 911 call wasn’t made until hours later, saying they could not give a reason why, and would not reveal who made it, citing the open investigation. 

A police officer stands by a memorial in front of the off-campus home where the four University of Idaho students lived.James Keivom for NY Post

Initially the local police said they believed the attack was “targeted” and there was no immediate threat to the local community — but now appear to have backtracked.

Chief James Fry speaks during a press conference about the deaths. AP

Although the FBI is best known for investigating interstate and federal crimes, it is often brought in to assist smaller police forces when a crime of magnitude happens, as it has access to resources and technology a local force may not.

Latah said Thursday that “investigators do not know who that person is,” referring to the murderer.

Here’s the latest coverage on the brutal killings of four college friends:

• University of Idaho murders update: What we know so far

Police are also in search of a murder weapon, and believe it might be a “Rambo”-style knife, a local store owner said.

Moscow Building Supply general manager Scott Jutte told the Idaho Statesman that a police officer came into his store to inquire about the sale of a KA-BAR brand combat blade.

Jutte said the knife in question was used by US Marines in the 1940s and is “similar to the knife Rambo has.”

FBI Director Christopher Wray has lost the confidence of rank-and-file FBI agents after a senior bureau official left under a cloud of accusations that he shielded Hunter Biden’s laptop from a criminal probe — and some believe the top G-man should step down, a new report says.

“I’m hearing from [FBI personnel] that they feel like the director has lost control of the bureau,” Kurt Siuzdak, a lawyer representing FBI whistleblowers, told the Washington Times in a report published Tuesday. “They’re saying, ‘How does this guy survive? He’s leaving. He’s got to leave.’

“[The FBI agents] are telling me they have lost confidence in Wray. All Wray does is go in and say ‘We need more training and we’re doing stuff about it,’ or ‘We will not tolerate it,’” Siuzdak said.

His comments come in the wake of Timothy Thibault, the top agent in charge of the FBI field office in Washington, resigning amid claims he blocked investigations into the first son’s laptop. Thibault’s lawyer said his resignation was unrelated to these claims and that he did not seek to close the laptop investigation.

Thibault was escorted out of the field office last Friday by “headquarters-looking types,” the Washington Times reported, while U.S. officials said this is common practice for anyone who retires.

Siuzdak told The Post that he left the bureau in March after a 25-year career, because management failed to hold bosses accountable, a problem that stems from politicization at the highest levels of the agency. 

He told the Times that the whistleblowers have alleged that Wray, who was appointed by President Donald Trump in 2017, did not take action when confronted with issues inside the bureau that ranged from agents being forced to sign false affidavits to sexual harassment claims. 

The FBI searched for and seized documents from former President Donald Trump’s Mar-a-Lago estate in Florida. AP

The FBI, which has been taking heat for the Aug. 8 raid on Trump’s Mar-a-Lago resort in search of classified documents, emphasized the integrity of its agents in a statement to the Times. 

“The men and women of the FBI work hard every day to protect the American people and uphold the Constitution. All employees are held to the highest standards of professional and ethical conduct, and we expect them to focus on process, rigor, and objectivity in performance of their duties,” the statement said.

“Allegations of misconduct are taken seriously and referred to the Inspection Division or appropriate investigative body,” it said.

Wray, at a Senate Judiciary Committee hearing earlier this month, called allegations that Thibault blocked an investigation into Hunter Biden’s laptop “deeply disturbing.”

FBI Director Christopher Wray testified at a Senate Judiciary Committee hearing earlier this moth. AP

Sen. Chuck Grassley (R-Iowa), the ranking Republican on the panel, wrote to Wray and Attorney General Merrick Garland in July to raise accusations from whistleblowers that the agency is burying “verified and verifiable” information about President Biden’s son by incorrectly labeling it as “misinformation.”

The Iowa senator said in his missive that if the accusations are true, the FBI and the Justice Department are “institutionally corrupted to their very core.”