A Chatham, Ont., man who left his live-in girlfriend after buying a winning lottery ticket worth $6.1 million has been awarded half the prize, but the battle for the remaining jackpot is most likely heading to court.

Maurice Thibeault will be granted approximately $3.07 million, according to a letter sent from the Ontario Lottery and Gaming Corporation to his ex-girlfriend, Denise Robertson, and obtained by CBC News.

"As you have claimed entitlement to one-half of the Prize, being approximately $3.07 million, OLG will retain this portion of the Prize," the letter from OLG investigations general manager Tom Scott says. "The other one-half prize share is undisputed by you and it is OLG's intention to pay this share to Maurice Thibeault."

OLG plans to hold on to the disputed prize money for 45 days, but if a resolution is not reached, the disputed funds will be paid into court, according to Scott. That means the money will be held by the Superior Court of Justice until a judge orders that it be paid out.

Payout 'unfair' says lawyer

Robertson and Thibeault had been living together for 2½ years and had been long been buying tickets together, according to her lawyer, Steve Pickard.

"We firmly believe she's absolutely entitled to one half of that lottery winning," he said. "At this point, there's no settlement and I don't know of any common ground right now. It's likely going to end up in court."

Whenever they had bought a ticket, they had always shared the winnings. -Steve Pickard , lawyer for Denise Robertson

Pickard said the OLG's decision to grant Thibeault millions may give him an advantage as the legal fight for the winnings continues.

"We do not dispute that he's entitled to half, but we feel ... he now gets the benefit of his half being paid to him and she's being put in a position where she's going to have to fight a legal battle for her half, and that seems a bit unfair," he said.

Neither Thibeault nor his lawyer, Richard Dinham, returned requests for comment Monday evening.

Dreams of winning the lottery

Robertson claims the couple had long dreamed of winning the lottery together and using their prize to build a large shop where they could fix up muscle cars.

When she heard on Sept. 20 that two winning Lotto 6/49 tickets had been sold — one in Chatham and the other in Quebec — she excitedly texted Thibeault about the possibility of winning half of the $12-million jackpot.

Robertson also entered screen shots of text messages between her and Thibeault as evidence he knew about the winning ticket as exhibits in her case claiming part of the $6.1-million jackpot. (Dan Taekema/CBC)

But when he got home, Robertson said Thibeault "made it clear" they did not win, according to the affidavit.

Four days later, he left for work and did not return. In court documents, Robertston alleges she came home to find his clothes and passport gone.

"When I look back, I recall that he did approximately 15 loads of laundry of all his clothes the night prior … as if he was preparing to pack up and leave," she added.

Robertson filed and was granted the court injunction on Sept. 28. She alerted the OLG to the disagreement over the jackpot.

An 'office pool' situation

Pickard clarified that her claim to the remaining prize money is based on their years of playing the lottery together and has "nothing to do with marital status."

"It's not that they were common law. The issue here is that they were partners in purchasing tickets, very much like an office pool situation," he said. "They didn't care amongst themselves who went to the store to buy the ticket. They just knew that they were buying their ticket, together. They had always done that and whenever they had bought a ticket they had always shared the winnings."

