Washington (CNN) President Donald Trump's personal attorney Michael Cohen has declared a payment he orchestrated to a porn star to be "lawful," but legal experts say the matter is far from settled.

Cohen said in a statement Tuesday evening that he facilitated a $130,000 payment to Stephanie Clifford, better known as Stormy Daniels, in 2016. His statement followed a legal complaint from the campaign finance watchdog Common Cause, which called for investigations into whether the payment -- reportedly made to stop Clifford from speaking about an alleged affair with Trump in 2006 -- violated campaign finance law.

The statement came as confirmation that the payment had been made, and it added more evidence and scrutiny to the accounts first raised last month in The Wall Street Journal about the alleged affair and payment, which Cohen has denied was linked to an affair. Cohen has said that Trump "vehemently denies" any encounter with Clifford, and Cohen released a statement from Clifford last month denying an affair with Trump.

In Tuesday's statement, Cohen said, "In a private transaction in 2016, I used my own personal funds to facilitate a payment of $130,000 to Ms. Stephanie Clifford. Neither the Trump Organization nor the Trump campaign was a party to the transaction with Ms. Clifford, and neither reimbursed me for the payment, either directly or indirectly. The payment to Ms. Clifford was lawful, and was not a campaign contribution or a campaign expenditure by anyone."

When asked why he made the payment, Cohen told CNN: "Just because something isn't true doesn't mean that it can't cause you harm or damage. I will always protect Mr. Trump."

Campaign Legal Center general counsel Larry Noble, a CNN contributor and former Federal Election Commission general counsel, said one of the top questions now is "Where did the money come from?"

"It's not usual for an attorney representing someone to pay out of his own pocket," Noble said.

Noble, along with Sunlight Foundation executive director John Wonderlich and University of California, Irvine, law professor Rick Hasen, noted in separate interviews that the statement was carefully worded and left open the possibility that Trump had personally reimbursed Cohen or the source of the funding was a third party.

"The biggest point to me is the denial was very specific and leaves open that Donald Trump himself was involved," Wonderlich said.

Hasen, meanwhile, said the key revelation from the statement is Cohen admitting he had facilitated the payment, confirming the news reports.

But he cautioned, "There are questions about who ultimately made the payment."

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Campaign finance law requires campaigns to disclose their contributions and limits donors to $2,700 per election. The Common Cause complaint asserts that if the payment to Clifford was done to influence the election, it would be an undisclosed "in-kind" contribution to the campaign, and if not from Trump personally, it would violate not only the disclosure rules but also the donation limit.

Hasen said that in addition to who had made the payment, a key point would be demonstrating whether the payment was campaign-related.

"It turns on the question of motive," Hasen said.

Common Cause maintains that Cohen's statement is an apparent confirmation of him violating campaign finance law because it was an effort to influence the election by keeping Clifford from speaking to the public about the alleged affair, and the organization renewed its calls for the FEC and Justice Department to look into the matter.

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However, it is unclear what the FEC or Justice Department might do. The FEC commissioners must vote to open an investigation, and given the partisan breakdown of the committee and its recent voting pattern, Noble predicted last month that it would likely opt not to investigate. He said Wednesday that the statement from Cohen could give commissioners who were leaning against investigating "something to latch onto," but he warned it was not a sure thing they would not vote to investigate.

Hasen said that while it is "unclear" what the agency might do, "not only is the FEC divided, it is also shorthanded."

On the Justice Department side, the experts said, the payment to the porn star called to mind the unsuccessful case against Democratic former Sen. John Edwards of North Carolina, in which prosecutors accused Edwards of violating campaign law to keep an affair under wraps as he ran for president in 2008. Jurors ultimately acquitted Edwards on one count and were deadlocked on five others. Since the Edwards case, the Justice Department's efforts in other high profile, politically charged cases have not fared better. The Supreme Court in 2016 vacated a corruption conviction for GOP former Virginia Gov. Bob McDonnell, and earlier this year prosecutors declined to retry Democratic Sen. Bob Menendez of New Jersey on conspiracy and bribery charges after his corruption trial ended in a hung jury.

Suffice it to say, Noble said, the Justice Department has not had "great luck" recently in this area.

Wonderlich said, however, he thought the payment might be a concern to some degree for the special counsel investigation led by former FBI Director Robert Mueller into Russia's meddling in the 2016 US election and whether it had colluded with the Trump campaign.

"That's the kind of arrangement that would be concerning," he said. "How many other illicit payments has Trump made?"

Wonderlich said he thought Cohen releasing the statement suggested they see some kind of hazard but that it was always possible Trump had demanded the statement in some attempt to persuade the public.

Asked why Cohen would have released the statement, Hasen said, "I think he probably thought this was the best way to handle it."

But he added that it was "not clear" to him that it was.