WASHINGTON — Sergei Krivov, the security officer who died mysteriously at the Russian Consulate in New York on Election Day, died due to internal bleeding related to a tumor, the New York City Medical Examiner says.

Though the New York City Police Department said Krivov was found dead with a head wound on the morning of November 8, Election Day in the US, the medical examiner’s office said it did not find evidence of a head wound on Krivov’s body, and that he died of natural causes.

“The medical examiner’s findings do not include head trauma,” Julie Bolcer, a spokesperson for the medical examiner’s office, said in an email, after BuzzFeed News asked why the head trauma wasn’t included in the office’s conclusion. “The medical examiner did not find that. That is not in the findings.”

BuzzFeed News has also learned that the FBI helped probe Krivov’s death, despite telling BuzzFeed News in February that it did not. A US Intelligence official said the bureau took part in a joint inquiry into the incident with the NYPD, and did not find Krivov’s death to be suspicious.

Pressed about the discrepancy, the FBI did not respond. The NYPD also did not immediately respond to a request for comment.

Initial reports said Krivov had fallen to his death from the roof of the consulate, but consulate officials quickly changed the narrative and said Krivov had a heart attack, fell, hit his head, and died. Despite the medical examiner’s office leaving the case open until Tuesday, the NYPD closed the case without a formal cause of death.

That the medical examiner’s office didn’t note Krivov’s head trauma may be explainable, but it is odd. If police had put the presence of a head wound into the incident report, the medical examiner should have at the very least explained why it wasn’t an issue.

“They should [acknowledge it],” said Marq Claxton, a former NYPD detective. “As part of the autopsy, they’re going to look at the complaint report if there’s anything special, if they’re going to be looking for anything specific.

“If it was that obvious, they should’ve noted it in their autopsy record and then dismissed it by further examination.”

Asked to directly address the discrepancy, the medical examiner’s office declined to specifically explain.

“For your guidance, the medical examiner’s office conducts its own independent investigation, including reviews of preliminary information from police where applicable, and arrives at a scientific and medical conclusion,” Bolcer said, referring further questions to the NYPD. “Yes, it is possible that what the medical examiner ultimately finds may differ from the preliminary police information, that is the nature of the investigative process.”

Krivov was a 63-year-old security officer at the diplomatic compound on the Upper East Side, whose responsibilities included access to the Russian mission’s top-secret crypto-gram, a device used to encode and decode secret messages sent between the consulate and Moscow. Although he was described as a Manhattan resident, there was no trace of Krivov in public records. The address NYPD had on file for him was not a residence.

The NYPD said Krivov’s death did not look suspicious, and closed the case. Two sources familiar with the matter said Krivov appeared to have a drinking problem, and said the death looked natural.

The morning of Krivov’s death was a time when Russia was at the forefront of Americans’ minds. Hours after Krivov died, Donald Trump would be elected president of the United States, an outcome that the US intelligence community would later say Moscow sought through an elaborate intelligence operation built to manipulate the US election.