According to the Belfast Telegraph, former two-division world champion Carl Frampton has issued legal proceedings against ex-manager Barry McGuigan.
Frampton, who split with McGuigan last year, filed his documents at the High Court in Northern Ireland in connection with alleged earnings from some of his bouts. The complaint was filed against McGuigan, his wife Sandra McGuigan and Cyclone Promotions (UK) Ltd.
The case is a counter-claim to McGuigan's ongoing legal suit against Frampton.
Frampton and McGuigan split last summer - a few months after the boxer suffered his first career defeat at the hands of Leo Santa Cruz at the MGM Grand in Las Vegas. The boxer also split with trainer Shane McGuigan, who is Barry's son.
After their split, McGuigan filed a legal case against Frampton for breach of contract - and at the time the boxer's legal team promised that a counter-claim would be filed at some point in the near future.
Frampton has signed a promotional deal with Frank Warren and hired Jamie Moore as his new head trainer.
He attempted to secure a trilogy fight with Santa Cruz in Belfast, but they were unable to reach an agreement.
Frampton made his debut under Warren's banner on November 18, also at the SSE Arena, and won a very tough decision over Mexican contender Horacio Garcia.
At the moment, Frampton is training for a scheduled ring return in April against former world champion Nonito Donaire at the SSE Arena in Belfast
Before their legal war continues, both sides are waiting for a ruling to be made on whether the case should be heard by a court in Belfast or London. Arguments on that preliminary point are expected to be heard later this month.
A spokesman for Cyclone Promotions told the newspaper: "The issues between the parties are subject to litigation and therefore it is not appropriate to comment at this time."