An investigation into the plane crash which killed footballer Emiliano Sala will focus on the validity of the pilot's licence.

Sala, 28, and pilot David Ibbotson, 59, died in the crash when their plane went down over the English Channel on January 21.

A body found in the plane wreck was brought to Portland Port earlier this month and was formally identified as that of the Argentinian footballer by HM Coroner for Dorset on February 7.

In its interim report the Air Accidents Investigation Branch (AAIB) has named "regulatory requirements" as one of four areas in which it will carry out further work before publishing its final report.

The AAIB noted that the type of licence held by pilot Mr Ibbotson meant he could only fly passengers in the European Union on a cost-sharing basis, rather than for commercial flights.

Pilots with his licence "must have a bona fide purpose for making the flight", according to the AAIB.

The Argentinian footballer signed for Cardiff City from French club Nantes for £15 million on January 18.

Mr Ibbotson, of Crowle, Lincolnshire flew Sala from Cardiff to Nantes the following day, with the return flight - which crashed in the Channel - on January 21.

The AAIB stated that the Piper Malibu aircraft took off at 7.15pm GMT and flew on its planned route at an altitude of 5,500 feet until it was around 13 nautical miles south of Guernsey at 8.02pm.

At that point, the pilot requested permission from air traffic control to fly at a lower level to maintain visibility.

He was cleared by the controller to fly at 5,000 feet, and when asked if a further descent was required, Mr Ibbotson responded: "Negative. Just avoided a patch there but back on heading 5,000 feet."

The last radio communication received from the aircraft was at 8.12pm when the pilot asked for and was granted permission to reduce altitude again.

Radar readings show the aircraft turned left and right, descended gradually and climbed rapidly in the minutes before it crashed at 8.16pm.

The AAIB stated that a band of showers, some heavy, passed through the area flown by the plane around the time of the crash.

Sala's body was recovered on February 6 but Mr Ibbotson has not been located.

The latter's family hope a fresh search for his body will begin this week after setting up an online fundraising campaign which has reached £250,000.

The aircraft remains underwater off the coast of Guernsey after an attempt to recover it was hampered by bad weather.