According to the lawsuit, which is a class action lawsuit in which several people have joined forces, Ronaldo's advertising allegedly enticed people to make investments that ultimately became loss-making businesses.

In November last year, Binance launched a collection of NFTs – digital certificates of authenticity – in partnership with the 38-year-old Portuguese, who himself stated that the collection was a reward to fans "for all the support over the years".

The cheapest of these NFTs cost $77 – a year later, the value has dropped to around a dollar.

The people behind the lawsuit point out, among other things, that Ronaldo's marketing has led to "a 500 percent increase" in the number of internet searches for Binance.

They also believe that the soccer star was required to state how much he was paid for the advertisement, which he did not do.

Ronaldo's stance on the allegations is unclear.

Binance entered the crypto market in 2017 where it has held a strong position ever since. Recently, however, it has come under fire and been accused of trying to circumvent regulations and mismanaging customers' assets.

Earlier in November, Changpeng Zhao, the CEO of the crypto exchange, pleaded guilty to money laundering offences. In addition, the company entered into a settlement with the U.S. Department of Justice – which resulted in a fine of USD 4.3 billion, equivalent to approximately SEK 45 billion.

CLIP: Ronaldo struck with acclaimed lob goal

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See Ronaldo's art goal in Saudi Arabia. Photo: AP and TT.