Joe Calzaghe outside the High Court in London during the case
The boxing promotion company Sports Network Limited has gone into administration, BBC Sport has learned.
The news follows last month's High Court case, which ordered Sports Network Limited to pay former world champion Joe Calzaghe £1.8m.
Calzaghe launched his High Court case after falling out with Sports Network Limited chief executive Frank Warren.
Calzaghe, owed money from his bout with Bernard Hopkins, has now instructed his lawyers to recover the funds.
"We are in contact with the administrators to ensure that there is a full and rigorous investigation of Sports Network's assets," said Andrew Forbes, Calzaghe's solicitor.
"Joe will pursue every angle to make sure he is paid the money he's owed and to put an end to this sorry episode, which blights his retirement and extraordinary legacy in the ring."
Calzaghe added: "No one ever took my titles from me in the ring and I am not about to let anyone take away the money that I earned in it for my family."
The 37-year-old Welshman retired undefeated in February, with 46 wins from 46 fights.
The Newbridge fighter held the WBO, WBA, WBC and IBF super-middleweight belts during a professional career that lasted 18 years.
A spokesman for Sports Network Limited told the BBC: "Sports Network Limited has been placed into administration. Sports Network Europe and Frank Warren Promotions will continue trading as normal."