ISTANBUL — Iran said Monday that it was halting cooperation with Ukraine in the investigation of a downed airliner after Ukrainian media published an audio recording that showed Iranian authorities knew immediately about the missile strike that brought down the plane, killing all 176 people on board.

A leaked audio file and transcript were published late Sunday by Ukraine’s 1+1 television channel. They included an exchange between an Iranian air traffic controller and a pilot who said he saw a missile hit Ukraine International Airlines Flight 752 on Jan. 8.

“Flares on route, as if from a missile,” the pilot of an Aseman Airlines flight from Shiraz to Tehran said to the controller, according to the transcript.

The controller responded that the tower was not informed of any missile activity in the area.

“That surely is light from a missile,” the pilot said. Later he said, “We saw an explosion, a big flare from the explosion.”

Iran for days denied that its forces had fired an antiaircraft missile and shot down the plane, a Boeing 737-800, shortly after takeoff from Imam Khomeini International Airport in Tehran. The incident came just hours after Iran’s Revolutionary Guard Corps fired more than a dozen ballistic missiles at military bases hosting U.S. troops in Iraq — retaliation for a U.S. drone strike that killed a prominent Iranian general at the Baghdad airport days before.

On Monday, Ukrainian and Iranian authorities both confirmed the authenticity of the Persian-language recording and said it was shared with Ukraine as part of the investigation of the crash.

“The recordings were part of the documents handed over to Ukrainian authorities,” the director in charge of accident investigations at Iran’s Civil Aviation Organization, Hassan Rezaifar, was quoted as saying.

“According to national and international regulations, they are classified documents, and the decision to publish them is surprising,” he said, according to Iran’s Mehr News Agency. “So we are not going to continue to provide them with documents.”

The recording is the latest revelation to embarrass Tehran in the wake of the crash. In the immediate aftermath, Iran’s armed forces waited four days to admit responsibility for downing the airliner. The shoot-down and the government’s initial false denials sparked protests in Tehran and other cities and prompted several officials to issue public apologies.

In the leaked exchange, the pilot correctly identified the location of the explosion, near the city of Karaj.

“Should anything like this be happening here?” he said to the controller.

“We were not informed of this,” the controller responded. “What does the light look like?”

“That surely is the light from a missile,” the pilot said.

“It’s not flying toward [Tehran], is it?” the controller asked. “Ukraine International Airlines 752, do you read?”

The investigation has also been marred by disagreements between Ukrainian and Iranian authorities, including over how to handle data from the flight recorder.

In a television interview Sunday, Ukrainian President Volodymyr Zelensky said Iran offered $80,000 in compensation per victim, which he rejected. He intends to sue for a larger sum in international court, he said. Eleven of the victims were Ukrainians, including all nine members of the flight crew.

“I think it is not enough,” he told the 1+1 channel. “A human life cannot be measured in monetary denomination, but we will press for bigger compensation.”

Zelensky also said the plane’s “black boxes” should be examined in Ukraine, but Iran has refused to hand them over, instead suggesting that Ukrainian investigators travel to Tehran to decode them.

Kyiv sent a team of 45 experts and search-and-rescue personnel to Tehran a day after the crash to assist in the investigation. It later released photos from the crash site showing shrapnel damage to parts of the wreckage.

The work of the investigators undercut Tehran's ability to deny any role in the crash, the secretary of Ukraine's National Security and Defense Council, Oleksiy Danilov, told The Washington Post last month.

Khurshudyan reported from Moscow.