Footballer Emiliano Sala was killed when the unlicensed pilot of his plane lost control and flew too fast as he tried to avoid bad weather, British aviation investigators said on Friday 

The 28-year-old Argentine had been en route from Nantes in western France on January 21 last year to make his debut for Premier League team Cardiff City when the small aircraft he was traveling in disappeared over the English Channel. 

The Air Accidents Investigation Branch (AAIB) said in its final report into the crash that the single-engine Piper Malibu aircraft suffered an in-flight break-up and plunged in to the water, north of Guernsey, upside down. 

The AAIB also confirmed that pilot David Ibbotson, 59, was unlicensed to fly that particular aircraft and at night, when the tragedy occurred. 

He was also operating an unlicensed commercial flight and being paid an unspecified amount for the flight, which was illegal. 

Investigators said it was likely that he was affected by carbon monoxide. 

An interim report also found that Sala had suffered carbon monoxide poisoning before the plane crashed and was likely unconscious when it hit the water. 

Geraint Herbert, senior inspector of air accidents at AAIB said two main factors contributed to the crash. 

"One was that the pilot was not experienced and qualified to fly the flight, but the other one of course was that he was probably suffering from carbon monoxide poisoning," he said. 

"We have made a recommendation to the regulators to require the carriage of carbon monoxide detectors on aircraft such as this." 

Sala had signed for Cardiff in a 15-million-Euro deal completed just a few days before the crash. 

In a statement, Cardiff City said it "welcomed" the report which "raises a number of new questions which we hope will be addressed during the inquest recommencing next week." 

Sala's body was found several days after the crash, attached to wreckage from the plane, while Ibbotson's body was never found. 

(With input from agencies)