The US government has sold a one-of-a-kind Wu-Tang Clan album previously owned by a drug firm executive once dubbed the "most hated man in America".

Martin Shkreli, who became notorious for hiking the price of a life-saving drug, bought Once Upon a Time in Shaolin for $2m (£1.4m) in 2015.

The hip-hop record was marketed by the Wu-Tang Clan as a unique piece of art.

Shkreli handed it over to US prosecutors in 2018 after being convicted of defrauding investors.

Its sale means the former drug firm executive had now fully paid off a $7.4m forfeiture deal, acting US Attorney Jacquelin Kasulis said in a statement.

However, due to a confidentiality agreement with the buyer, prosecutors did not say who had since bought the album from the US government, or for how much.

Shkreli's lawyer told news outlet CNBC that the sale price was "substantially more" than what his client had paid for it.

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Wu-Tang Clan began working on the album in the late 2000s, and it took six years to complete. Recorded in New York City and produced in Marrakech, it includes appearances from pop artist Cher and Game of Thrones actress Carice Van Houten.

Feeling that the value of music had been cheapened by online streaming and piracy, the group decided to release one copy of the album, "adopting a 400-year-old Renaissance-style approach to music, offering it as a commissioned commodity".