Police say two men and one woman were charged Wednesday in the case, while another man was arrested Thursday and faces similar charges.
Among those charged was 20-year-old Bianca Rojas-Latraverse.
Philippe Jette, one of the poker player's agents, said she dated Duhamel a few months ago.
"(He) was seeing Bianca over a short period of time," Jette said.
"She is the only one of the four suspects Jonathan knew."
Duhamel became internationally known in 2010 when he won US$8.9 million in a poker tournament in Las Vegas, making him the first Canadian to capture the Main Event at the World Series of Poker.
During a brazen home invasion and robbery on Dec. 21, Duhamel's championship bracelet and a high-end Rolex watch given to him as a present were stolen, along with cash.
Duhamel was also tied up and badly beaten during the attack at his Boucherville district condo, just south of Montreal.
After the attack, he spent part of the day in hospital being treated for his injuries but was quickly released.
Police said Thursday they were able to find the Rolex — but not the coveted gold-and-diamond bracelet.
Authorities said tips began pouring in after the home invasion and after Duhamel offered a reward last week of up to $10,000 for information leading to the recovery of his possessions or to the arrests of those responsible.
"Investigators received information from the public and with this information we were able to make an arrest on Saturday," said Longueuil police Const. Mark David.
"During the investigation, the Rolex watch was seized but we're still looking for the bracelet he received for the poker championship."
Rojas-Latraverse was the first person arrested — last Saturday. She faces five charges, including conspiracy.
John-Stephan Clark-Lemay, 22, and Andre-Robert Perron, 26, were arrested in Pointe-Claire, in western Montreal, on Monday night.
The three appeared in court Wednesday in Longueuil to face a variety of charges that included break and enter, armed robbery, aggravated assault, unlawful confinement and receiving stolen goods.
A fourth person, Anthony Bourque, 20, was arrested early Thursday and was also charged in the attack.
Police wouldn't confirm that the female suspect was Duhamel's ex-girlfriend.
They did say, however, that Duhamel didn't know either of the actual intruders who burst into his home and attacked him.
"The two individuals that went to his home that day — Mr. Duhamel did not know these people," David said.
Duhamel's agent said his client was relieved that arrests had been made and thanked police for their work.
"With great relief, we are very, very, very happy that the investigation moved so quickly," said Jette.
In addition to the missing bracelet, police said they hadn't found any of the stolen cash.
Of the missing money, some was in Canadian currency while some was in the form of 500-euro notes — a very rare denomination in North America.
It's unclear if the reward offered by Duhamel will be handed out to anyone. Jette said a decision would be made after a review of the information and the person who supplied it.
Duhamel promised to be back in action soon after taking the holidays to recover from his injuries.
Last January, he won the high-roller event at the European Poker Tour, taking home more than $270,000. He later won more than $40,000 at the World Series of Poker, bringing his total winnings so far to more than $9.5 million.