A Senate candidate nicknamed “Decoy Dan” is under investigation by Alaska election officials amid allegations that he entered the race to confuse voters and siphon support from Republican Sen. Dan Sullivan, a key ally of President Donald Trump.

Alaska Lt. Gov. Nancy Dahlstrom announced Monday that the state has opened a formal investigation into Daniel James Sullivan Jr., a Petersburg resident who recently launched a campaign for the U.S. Senate while sharing the same first and last name as the incumbent senator.

The probe will determine whether Sullivan’s candidacy was filed in “good faith” or whether it was part of a deliberate effort to mislead voters ahead of Alaska’s Aug. 18 primary election.

“The Division of Elections has a fundamental obligation to protect the integrity of Alaska’s elections and ensure voters are not deceived about the identity of the candidates on their ballot,” Dahlstrom said in a statement announcing the investigation.

In a letter sent to Sullivan, Dahlstrom said state officials are examining what she described as “credible allegations” that the candidate entered the race to exploit voter confusion by sharing both the name and party affiliation of the sitting senator.

“There are credible allegations that you declared your candidacy in coordination with another candidate and campaign out of intention to confuse and manipulate voters by capitalizing on the fact that you share a first and last name with the incumbent senator and have selected the same political party affiliation,” Dahlstrom wrote.

The controversy erupted after Daniel J. Sullivan switched his candidate filing to Republican shortly before entering the race, placing him on the ballot alongside Sen. Dan S. Sullivan, the Republican incumbent seeking a third term in the Senate. Critics say the move intensified concerns that voters could mistakenly support the wrong candidate.

The National Republican Senatorial Committee has also weighed in, urging Alaska election officials to reject the candidacy. In a letter to state election authorities, NRSC General Counsel Blake Murphy argued that the filing appears designed to “confuse voters and undermine confidence” in the election process.

Sen. Sullivan’s campaign has accused Democrats of orchestrating the effort to benefit former Democrat Rep. Mary Peltola, who is mounting a high-profile challenge in one of the nation’s most closely watched Senate races. Republicans currently hold a narrow Senate majority, making the Alaska contest a key battleground in the fight for control of the chamber.

“Everybody in Alaska knows I’m Dan Sullivan-R,” the senator said last week. “He’s purposely trying to trick my constituents.”

Peltola’s campaign has flatly denied any involvement.

“Our campaign has no involvement with either Sullivan campaign,” spokesman Harry Child told The Associated Press.

The Alaska Democratic Party has likewise denied any connection to the candidate.

For his part, Daniel J. Sullivan insists his campaign is legitimate and rejects claims that he is serving as a political decoy.

“I have every right to run for whatever office I’m qualified for, and I’m qualified for this office,” Sullivan told the AP. “I think I’m doing what most Americans would think would be a patriotic thing to do when you’re unsatisfied with the status quo.”

The challenger, a retired teacher and former U.S. Forest Service employee, said he has had “zero, none, zilch” contact with Peltola’s campaign or Democratic operatives and maintains that running for office was entirely his own decision.

The unusual dispute has drawn national attention because of the stakes involved. Sen. Sullivan, who has represented Alaska in the Senate since 2015, has been endorsed by President Donald Trump and is viewed as a crucial Republican incumbent in the battle for Senate control. Trump previously praised Sullivan for supporting his agenda and backed his reelection efforts.

Under Alaska’s election system, all candidates appear on the same primary ballot regardless of party, with the top four finishers advancing to the general election. While candidates will be identified by their middle initials on the ballot, Republicans argue that the presence of two Republican candidates named Dan Sullivan could still create significant voter confusion.

State officials have not yet announced whether Daniel J. Sullivan will ultimately be allowed to remain on the ballot. The investigation remains ongoing.