Federal officials on Tuesday blamed Mayor de Blasio for a fatal sex attack on a 92-year-old Queens woman — saying his “sanctuary city” policy kept the accused killer from being held for deportation last year.

“It was a deadly choice to release a man on an active ICE detainer back onto the streets after his first arrest included assault and weapon charges, and he now faces new charges, including murder,” said Thomas Decker, New York field-office director of enforcement and removal operations for US Immigration and Customs Enforcement.

“New York City’s sanctuary policies continue to threaten the safety of all residents of the five boroughs as they repeatedly protect criminal aliens who show little regard for the laws of this nation.”

ICE said it lodged a detainer request with the NYPD for Reeaz Khan, an illegal immigrant from Guyana, on Nov. 27 — the same day he was busted for allegedly attacking his dad during a fight in their South Richmond Hill home.

Khan, 21, was accused of using a broken ceramic mug to slash the chest and arm of his father, 41, who then had to be hospitalized.

Khan was charged with misdemeanor assault, criminal possession of a weapon and harassment, and released without bail after being slapped with a temporary order of protection for his dad, records show.

About six weeks later, Khan was busted in the sexual abuse and slaying of Maria Fuertes, 92, after she was found with her clothes pulled above her waist and near death on a Richmond Hill sidewalk at about 2 a.m. on Jan. 6.

Fuertes had been lying in the 32-degree weather for about two hours after being sexually assaulted and strangled, law-enforcement sources have said. She was taken to Jamaica Hospital Medical Center, where she died from injuries that included a broken spine and rib fractures, according to court papers.

Cops received several tips identifying Khan as the attacker — including one from his brother — after releasing surveillance video, and he allegedly implicated himself before being arrested last Friday.

Khan told detectives before he was charged that he found Fuertes lying on the ground and was trying to help when he “fell down, his belt broke, his pants fell down and his penis fell near her vagina,” Assistant District Attorney Joseph Grasso said at Khan’s arraignment on two counts each of second-degree murder and first-degree sexual abuse. “Defendant then stated that he did lift up her skirt and tried to put his penis inside of her,” Grasso added.

A retired Brooklyn detective told The Post “it was only a matter of time before this would happen” under the sanctuary-city policy. “Maria Fuertes’ blood is on Mayor de Blasio’s hands,” the source added.

Under de Blasio’s sanctuary policy, illegal immigrants are turned over to ICE only if they’ve been convicted of any of 170 “serious or violent felonies.”

In a statement, the NYPD said it “did not receive an ICE detainer” regarding Khan, and de Blasio rep Olivia Lapeyrolerie said officials “mourn with the family of Ms. Fuertes,” adding, “It is shameful that the Trump administration is politicizing this tragedy.”

ICE has a fax confirmation receipt showing that the detainer request was sent to the NYPD’s Queens Central Booking unit at 7:41 a.m. on Nov. 27, ICE spokeswoman Rachael Yong Yow said.

The agency declined to release the receipt or the detainer request, saying confidential information had to be officially redacted first.