Swansea have confirmed that striker Besian Idrizaj has died at the age of 22.
The player's agent informed the Coca-Cola Championship club of the sad news on Saturday afternoon. Idrizaj is believed to have suffered a heart attack at his family home in Linz, according to reports in Austria.
A statement on Swansea's official website read: "Swansea City can confirm that the agent of young striker Besian Idrizaj has informed the club that the striker has sadly passed away.
"It is understood that the popular 22-year-old died in his sleep on Friday night while at home with his family in Austria.
"The exact cause of death has not been confirmed and our thoughts are with his family, friends and team-mates at this time."
Idrizaj, who joined Swansea in August 2009, previously spent three years with Liverpool, and had a year left to run on his contract with the Swans.
He did not feature for the first team during his time at Anfield, but had loan spells at Luton, Crystal Palace and Austrian outfit Wacker Innsbruck.
Idrizaj had suffered health problems in the past and collapsed on the pitch while playing for Wacker against Sturm Graz in February 2008.
Swansea are awaiting further details from Austria before commenting further on Idrizaj's passing.