The straphanger torched by an illegal migrant on a Brooklyn F train Sunday was so badly burned that authorities are still struggling to identify her two days after the horrific attack, prosecutors and sources said.

According to sources, the victim was asleep but alive when she was set ablaze at the Coney Island station, allegedly by Guatemalan migrant Sebastian Zapeta-Calil, and had a walker and some bags with her at the time — but cops struggled to pull fingerprints because of her scorched skin.

Brooklyn prosecutors said at Zapeta-Calil’s arraignment on murder and arson charges Tuesday that the “very badly burned” victim remains a Jane Doe.

Assistant District Attorney Ari Rosenberg said the medical examiner ruled the cause of death as “smoke inhalation and thermal injuries.”

“The defendant stated in sum and substance that he ‘drinks a lot of liquor’ and did not remember what happened,” Rosenberg said.

In a statement, the city medical examiner said the autopsy on the victim took place Monday.

“We continue to work with partner agencies to confirm the identity of the decedent, after which attempts will be made to contact next of kin before releasing details to the media,” the medical examiner said.

The sick caught-on-video crime shocked the Big Apple.