LONDON • Uefa has heavily criticised the World Anti-Doping Agency (Wada) for wrongly flagging a positive drug test by the Liverpool defender Mamadou Sakho after he took a fat-burner without the club's knowledge last year.

Sakho, who is now on loan at Crystal Palace, was suspended at the end of April last year after testing positive for higenamine following the second leg of Liverpool's Europa League last-16 tie against Manchester United the previous month.

However, in early June, Uefa's disciplinary body absolved Sakho of taking a performance-enhancing drug. On Thursday, European football's governing body went further still, releasing a damning report pointing out that higenamine is not specifically listed on Wada's prohibited list.

The report also suggested there are significant doubts among experts about whether higenamine is among a group known as beta2-agonists, all of which are banned by Wada.

It also pointed out that Wada's laboratories do not routinely test for the substance and that if Sakho's sample had been handled by the Lausanne laboratory and not Cologne's, then it would not have been tested for higenamine.

Wada spokesman Ben Nichols insisted that many of Uefa's criticisms were misplaced.

Sakho was suspended by Liverpool when Jurgen Klopp, their manager, and the club's owner, Fenway Sports Group, agreed it would be prudent to omit him from games while the investigation commenced, and he was then provisionally suspended by Uefa.

Among the games he missed was the Europa League final and he was also omitted from France's squad for Euro 2016.

THE GUARDIAN