New Wales manager Chris Coleman's former club Larissa are suing the Football Association of Wales over his appointment as the country's manager.
Within hours of Coleman being named successor to the late Gary Speed, the Greek club released a statement.
Coleman left Larissa citing their financial problems less than two weeks before taking the Wales role.
"We have started legal proceedings... to claim compensation from the Welsh FA," said Larissa's spokesman.
"We are also prepared to take the matter to Fifa."
The former Fulham and Coventry manager took over at Larissa in May 2011 and left eight months later.
"I left Larissa two points off the top of the league," Coleman said in his unveiling as the Wales manager.
"I left them because financially they are in big trouble. Some of the staff had not been paid for six months, eight months, up to a year."
But the Greek club's spokesman said: "On January 8, 2012, Chris Coleman gave his last interview as head coach of Larissa, saying the causes of his departure were unrelated to the national team of his country.
"Today, 11 days afterwards, it has been announced officially that he will be the new national coach of Wales.
"Once it became known that Chris Coleman, who has a contract until next June, would be leaving, the club has been heavily criticised despite the president saying publicly he did everything to keep Coleman at the club.
"Instead of asking for an apology from all those who criticised us, we instead feel the need to apologise for our choice in appointing Chris Coleman."
But the Press Association understands the FAW are confident that they and Coleman have been thorough and correct in all matters relating to his appointment, with Larissa's failure to pay Coleman and members of his staff due to their financial problems meaning they were in breach of his contract.