Chelsea are taking Juventus to a FIFA dispute panel this week to try to claim millions of pounds in compensation for former striker Adrian Mutu.
Romania international Mutu was sacked by Chelsea after testing positive for cocaine in 2004 and the club have been on a nine-year battle to reclaim the money they lost in signing him.
After serving a seven-month ban Mutu went on to sign for Juventus via Italian side Livorno - who acted as an intermediary because at the time Juventus had filled their quota of overseas players. The Swiss courts have ordered Mutu to pay compensation of 17.2million euros (£14.5m) to Chelsea but he has still not paid up, and the club is now pursuing legal action against Juventus and Livorno, holding them to be liable for payment because they signed him for nothing.
Chelsea had paid £15.8million to sign him from Parma and Juventus went on to sell him for £6million to Fiorentina.
The case is being held before FIFA's dispute resolution chamber in Zurich this week.
A Chelsea spokesman told the Press Association: "We are exercising our legal remedies to recover the amounts owed to us and we will continue to do so."
Chelsea have also taken legal steps to try to claim three properties bought by Mutu in Miami worth several million pounds in total.
Mutu, who is aged 34, currently plays in France's Ligue 1 for Corsican side Ajaccio. He has said he intends to retire at the end of next season.