A pilot taking pictures of himself in the cockpit may have led to a fatal plane crash in Colorado in May. 

An investigation by the National Transportation Safety Board (NTSB) concluded that the pilot was likely using a cellphone prior to the plane stalling and spinning before crashing into the ground. 

"It is likely that cellphone use during the accident flight distracted the pilot and contributed to the development of special disorientation and subsequent loss of control," the NTSB said.

Family members reported that Amritpal Singh was flying the plane with a musician as his passenger on May 31, 2014, shortly after midnight.

Although the pilot had 726 fight hours and 27 hours of experience flying at night, he lacked certification for flying at night with instruments and for carrying passengers at night.

Investigators also found a GoPro camera mounted to the plane's windshield, and evidence that Singh and his passengers took selfies in mid-air during previous flights. 

The night of the crash, the 29-year-old took a photo and used his cellphone while flying the plane. 

"During the climb-out portion of flight, the pilot uses his cellphone to take a self photograph," investigators said.

"The camera's flash was activated and illuminated the cockpit area.

"During the climb-out phase, the pilot was seen making keyboard entries to his cell phone and additional keyboard entries on a portion of flight consistent with the downwind leg."

While commercial pilots are forbidden from using their cellphones or other electronic devices during takeoff, landing, or when below 10,000 feet, there are no rules prohibiting private pilots from doing the same. 

"We expect pilots to operate safety, and our rules prohibit them from operating carelessly or recklessly," Federal Aviation Administration spokeswoman Laura Brown said.