Payet signed a five-year contract with the Hammers when he joined from Marseille for $A17.3 million in June 2015 and he made a positive impact in his first season, contributing nine goals and 12 assists in 30 Premier League appearances.

He extended his West Ham deal until 2021 in February 2016 but, after impressing for France at the European Championship, became unsettled during the subsequent campaign and returned to Marseille in January in a deal worth $A41.2 million.

Sullivan described the purchase and sale of Payet as "good business", saying: "We knew Dimitri was flawed, and that's why we got him for £10.5m."

"It was a fantastic buy, but we knew we bought a flawed individual and someone who could well go on strike - he had done it all before.

"That's why he never reached his full potential as a player and why big clubs have steered clear of him. But, I've got to say he was a fantastic servant for the club. He gave us 18 wonderful months, particularly the first 12 months."

Sullivan admitted he would have liked to keep the dead-ball specialist if he had not been causing unrest at London Stadium.

"We didn't want to sell him but we got around two and half times what we paid for him and you've got to say it is good business. It's not what we wanted but, as a club like West Ham, sometimes we have to sell," Sullivan added.

"We wouldn't have sold him unless we had to. We had meeting after meeting with him - he wanted out and the manager wanted him out. He [Slaven Bilic] didn't want to have an unhappy camp.

"Personally, I would have made him stick it out for six months and given him a hard time, but if the manger says he's unsettling the whole camp, you've got to support the manager."