Andy Webster has been cleared to make his debut for Wigan after Fifa gave the green light on his switch to the JJB Stadium.
The 24-year-old used a loophole in European employment law to leave Hearts at the end of last season, despite still being under contract for another year.
Wigan moved to bring Webster to England last month but had to wait for clarification from Fifa to select the player.
Fifa have now confirmed the deal, although a compensation package needs to be agreed at a later date.
Webster could now make his debut for the club against Portsmouth at the weekend and manager Paul Jewell is looking forward to having the Scotland international available for selection.
"I am relieved this issue is now almost resolved," said Jewell.
"It has taken many long hours of negotiation for Andrew to become a player at this club, but I'm convinced all the hard work will be worth it once the supporters see him play.
"He is a confident and committed defender who adds a huge amount of competition to the centre-back spots, which is extremely healthy for the club.
"It has been a difficult time for him as he's not had a full pre-season under his belt, spending a lot of the summer training on his own.
"But he has worked ever so hard in training, which is a tribute to his desire to feature as soon as possible."