DULUTH — The mayor of Two Harbors wants to build an underwater hotel in Lake Superior, and the Minnesota Attorney General's Office is being asked to decide whether he has made any unethical moves while promoting the idea with the help of an anonymous self-proclaimed billionaire.

The Two Harbors City Council had a special meeting Thursday to discuss whether Mayor Chris Swanson's tweets, podcasting and blogging violate communication protocol — whether in city code, charter, policies or state statute. The council decided unanimously to let the attorney general decide.

Robin Glaser, the council's vice president, said City Attorney Timothy Costley will be sending a letter to Minnesota Attorney General Keith Ellison's office to request a formal opinion.

Swanson, in his second term as mayor of the tourist destination along the North Shore, introduced the potential for unique lodging on a late August episode of "Ask a Billionaire" — a podcast that pairs entrepreneurs with a "billionaire recluse" who goes by the pseudonym Mr. O.

With just one of the town's two harbors, Agate Bay, used for shipping, Swanson suggested on the show that Burlington Bay might make a good place for growth — an idea he nicknamed "the eighth wonder of Lake Superior."

"What about an opportunity to put a facility in the water?" Swanson says on the podcast. "We started researching: What could that look like if we put lodging right into Lake Superior."

Swanson's brainstorm with Mr. O included rooms above and below water, a driving range, a helipad, SCUBA diving and a submarine.

"Would this all work?" Swanson asked. "As we dug in further and further, it got more exciting."

In the episode, Swanson points to his brother Joe Swanson, co-owner of Bluefin Bay, as another person interested in the proposal.

Mr. O, described early in the episode as a wealthy adviser who left the public eye years ago, has been mentoring Chris Swanson through the process and offered a price point during the episode: He estimated that the project could cost at least $400 million.

"It's an opportunity for people to buy into lodging facilities that will have a return on investment for them," Swanson said.

City officials are distancing themselves from the proposals.

"The city of Two Harbors has not been involved with Mr. O or any other anonymous individual on any current or proposed project," Glaser wrote in a statement. "Be assured that the city of Two Harbors will not engage in a project with an anonymous individual."

For the past two months, the mayor has been active on Twitter where he often posts about cryptocurrencies and Web3, an idea that would change the way people interact with the internet.

Vibrant Two Harbors, described as an initiative started by Swanson and Mr. O to turn the city into a destination site in the Midwest, has an incomplete website with some placeholder text and stock images. It also includes a form for interested investors.

Swanson did not return phone calls or an e-mail message Friday.