Six of the most successful Fifa video gamers on YouTube have been targeted by hackers.
Hackers stole millions of Fifa coins, which are virtual currencies for the games, and sold players worth thousands of pounds.
It is believed that they managed to convince the creator of EA Sports to transfer the victims' accounts to new email addresses controlled by the hackers.
Many other well-known players who do not upload videos are also believed to have been affected by the attack.
AnesonGib, W2S, Nepenthez, Nick28T, Bateson87, and matthdgamer have more than five million subscribers on YouTube.
Matthew Craig, the man behind the moniker matthdgamer, told the BBC: "There have been about 10 or more accounts that have been hacked over the last two weeks, including mine.".
In a video, Nick28T stated: "Basically, someone called and claimed to be me and ... gained access to my account.".
An EA spokesperson said: "We encourage all FIFA players to protect their accounts using authentication and identification, as we describe in our Help section and on our product websites.
"We are constantly working with our customer service team to improve security measures and account integrity, to ensure that players are trained on countermeasures in the event of an attack.".
Mr Craig said that the EA had apologised for the attack and had responded immediately to provide him with assistance from the moment he first reported the incident.
"The account was restored to me, they added some extra security measures and everything was fine," he said.
