Knock Out Investments, better known as Dutch fight management firm Golden Glory, filed a lawsuit in Clark County, Nev., Thursday alleging Alistair Overeem breached the terms of a five-year contract with the group.

The complaint, a copy of which ESPN.com has obtained, also names Overeem's representative Collin Lam as a defendant. The filing comes one day prior to Overeem's headlining clash against Brock Lesnar at UFC 141 in Las Vegas.

"We have a legal team," Lam told ESPN.com. "We have a great law firm in Las Vegas. A great law firm in LA. So they're taking care of everything."

Overeem is alleged to have not paid a 30 percent commission to Knock Out Investments following his win in Strikeforce against Fabricio Werdum on June 18.

Rather than following the arrangement Overeem and KOI used in previous bouts -- a promoter pays KOI, which in turn cuts a check to the fighter -- Overeem was directly paid his purse and win bonus totaling $170,000, which is standard practice when Zuffa LLC promotes events.

Six weeks after beating Werdum, Zuffa, which purchased Strikeforce in March, released Overeem from the final fight of this three-bout deal with Strikeforce.

Retained, however, were Zuffa's exclusive negotiating rights with Overeem. At the time Zuffa also parted ways with other Golden Glory-affiliated fighters, stating the Dutch firm's business practice of taking direct payment was antithetical to how the promoter operated.

Still, KOI negotiated with Zuffa for Overeem's services and he signed a contract with the UFC on Sept. 6.

In November, Overeem, through his counsel, sent a letter to KOI demanding monies owed. Overeem subsequently filed a lawsuit against the management group, asking for $151,000 and a court order to break the contract, which runs through July 2012.

In interviews at the time, Overeem stated he left Golden Glory, with which he maintained an 11-year relationship before signing with the UFC, over a breach of trust. He maintained he was taken advantage of by Golden Glory.

In the complaint filed against Overeem and Lam Thursday, KOI alleges that "subsequent to the execution of the UFC contracts, Overeem made numerous public statements that KOI/GG breached its fiduciary to him and that there was 'mistrust.' Overeem claimed that Zuffa's CEO, Lorenzo Fertitta told him in no uncertain terms that: there is a one million dollar 'signing bonus;' that the one million dollar signing bonus was Overeem's money and that KOI/GG was 'ripping him off' and 'stealing from him.'"

Caren Bell, a representative for the UFC and Fertitta, said they had not seen a copy of the complaint and could not comment.

The complaint does not state to whom Overeem made such claims. Lam, speaking for Overeem, declined to address specific allegations put forward in the 16-page document.

Pursuant to the terms of Overeem's UFC contract as outlined in the complaint, he is guaranteed a "bout fee" of $264,285 on Dec. 30. Should he defeat Lesnar, Overeem would receive an additional $121,428 "win bonus." Overeem is also in line to receive a $2 pay-per-view bonus per viewer, "for all revenues received by UFC-Zuffa for telecast of the Lesnar fight in the United States, Canada or over the internet in excess of $500,000."

Terms of the contract also guarantee Zuffa would pay Overeem $1 million spread out evenly over the first three fights of his deal, which is potentially good for up to eight bouts. Overeem is also expected to receive intellectual property payments for worldwide marketing of his likeness or image.

Lam, whom KOI's legal counsel Rod Lindblom called "instrumental in having Alistair move away from Golden Glory and breach his contract," said Overeem, 31, is aware of the legal action, which "we knew was coming," and remains squarely focused on Lesnar.

"The suit was filed for a very simple reason," Roderick J.Lindblom, legal counsel for KOI and Golden Glory, told ESPN.com. "Alistair Overeem has been part of Golden Glory for 11 years. Knockout Investment has a management contract with him. The management agreement was from 2007 until 2012. They negotiated one of the largest MMA agreements in the history of the sport for him. And within days he accused them of some pretty shady stuff that is not true. And he has walked away from his contract."

Josh Gross covers mixed martial arts for ESPN.com.