In this photo provided by Tasnim News Agency, a rescue helicopter flies over the Dena mountains while searching for wreckage of a plane that crashed on Sunday, in southern Iran, Monday, Feb. 19, 2018. Iranian search and rescue teams on Monday reached the site of a plane crash the previous day that authorities say killed all 65 people on board, Iran's Press TV reported.(Ali Khodaei/Tasnim News Agency via AP)

Rescue teams have recovered the black boxes of a plane that crashed last month in the mountains of southwestern Iran leaving 66 people dead, official media reported on Sunday. 

"The box that recorded flight parameters and the one with conversations in the cockpit have been handed over to judicial authorities," Reza Jafarzadeh, the public relations director of Iran's civil aviation organisation, told official news agency IRNA. 

Jafarzadeh said the two black boxes of the Aseman Airlines ATR-72 were found on Saturday by rescue teams, who had resumed search operations in the Zagros mountains on Friday after bad weather forced them to halt efforts for nearly a week. 

They were to be handed over to investigators seeking to determine the cause of the accident. The aircraft, on a domestic flight out of Tehran, went down in a snowstorm on February 18 and crashed at a height of about 4,000 metres (13,000 feet). 

There have been no reported survivors from the plane's 66 passengers and crew. 

The crash site has been hit by heavy snowfall in recent days, making rescue operations particularly dangerous due to avalanche risks, according to officials quoted by local media. 

So far, only body parts have been recovered from the scene of the crash. Forensic teams have performed tests on 51 samples of human tissue in attempts to identify the victims, IRNA reported.