Air crash investigators have released new photos showing the wreckage of the private aircraft that crashed in the English Channel last month, killing footballer Emiliano Sala and pilot David Ibbotson.
In a statement released alongside the photos on Monday, the UK's Air Accidents Investigation Branch (AAIB) said it was looking into special pilot licensing and aircraft permissions during its investigation.
"We have gathered evidence from radar, weather reports, video of the aircraft on the seabed and interviews with witnesses," the statement said.
"Some operational aspects are yet to be determined, such as the validity of the pilot’s licence and ratings."
The Argentine striker was en route to Cardiff to begin a new chapter in his career last month when the single-engine Piper Malibu aircraft he was aboard crashed into the English Channel.
A funeral was held in Sala's hometown of Progreso, Argentina, last week after his body was recovered from the sea bed.
Search efforts are still underway to find the body of missing pilot Ibbotson.
"We continue to speak to the families of the pilot and passenger to keep them updated on the progress of our investigation," the AAIB said.
"Our priority now is to go through the evidence, much of which is extensive and complex, so we can piece together what happened between the aircraft being lost from radar and it coming to rest on the sea bed."