Representatives for Christie and Cohen both declined to comment on the weekend fundraiser.
Christie has struggled to catch up in the election money race after a relatively poor showing in the early stages of his campaign.
The latest Reuters/Ipsos polls showed that Christie had less than seven percent support from respondents. Real estate businessman and television personality Donald Trump led the party's 17-strong field with the backing of 24 percent of Republican voters.
Potential long-term benefactors such as Cohen might be the life raft Christie needs to keep him in the race. But in Cohen's case, the association comes with its own controversy:
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Cohen, 59, is the owner of what was once a $14 billion hedge fund management company, SAC Capital Advisors LP, which for nearly a decade was the subject of a federal criminal probe into suspected insider trading.
The company eventually pleaded guilty to fraud related to insider trading and agreed to pay $1.2 billion to settle the charges. A subsidiary of the company was fined $600 million to settle a different insider trading case.
Cohen himself was never criminally charged, but the U.S. Securities and Exchange Commission has accused Cohen of failing to properly supervise his employees.
As part of the settlement with the government Cohen had to return client money and convert the company into a family office. He changed its name to Point72 Asset Management, which focuses exclusively on managing Cohen's own $11 billion fortune.
Earlier this year, the Wall Street Journal reported that Cohen attended an intimate dinner of about a dozen people for the outside spending group supporting Christie's candidacy, the Super PAC America Leads. Real estate developers James and Harrison LeFrak and businessman Nick Loeb would also attend Saturday's fundraiser, according to the invitation.