Nigerian forward Kanu has lodged a seven-figure claim against Portsmouth football club.
The 35-year-old has 12 months remaining on his contract with the cash-strapped outfit, who are trying to clear the eight remaining senior professionals from their wage bill.
Kanu believes that Portsmouth owe him a number of payments - dating back to 2006 - and his barrister Samuel Okoronkwo has blasted the club for claiming that the player had breached his contract by not reporting for pre-season training.
"He has regrettably been forced to serve the requisite notices of breaches of contract by the club, both historically and presently. This naturally leads to the Football League," said Okoronkwo. "He has been playing and scoring goals for Portsmouth for six years, sometimes playing through injury. Now he is being treated like this.
"He has lost millions of pounds since 2006 through genuine contractual obligations but has been prepared to wait. Now they are threatening breach of contract. [Portsmouth administrator] Mr Trevor Birch attended my office in May and said he did not want Kanu to stay at the club, which I found surprising, especially having waived millions of pounds he is entitled to.
"Then I received an e-mail on Saturday stating if he did not turn up for training on Monday he would be held in breach of contract."
Kanu has made 143 league appearances for Pompey, scoring 20 goals.
Robert Summerscales
