With just over two months left in his race for re-election, Representative Thomas Kean Jr. had an important guest joining him at a fund-raising event in New Jersey: Mike Johnson, the House speaker.

Mr. Johnson is trying to hang on to a Republican majority in the House after November’s midterm elections. Mr. Kean’s defense of his swing-district seat could help determine whether the speaker gets to keep his gavel.

But details about the event, like all of Mr. Kean’s campaign stops, had been kept under wraps. The congressman, whose national profile reached new heights earlier this year when he disappeared from public view for nearly four months with minimal explanation, has a reputation for being reticent with the news media. Mr. Kean does not release his schedule in advance, which can make reporting on his campaign events difficult. Even when the House speaker is coming to town.

Several dozen guests, most dressed in crisp suits and ties, began arriving at the Hawk Pointe Golf Club, a private 18-hole course in western New Jersey, before 8:30 a.m. for the breakfast fund-raiser.

Mr. Kean was the first of the politicians to appear. His wife, Rhonda, dropped him off at the front door. Mr. Johnson and a caravan of cars carrying his aides and security officers pulled up a few minutes later.

Inside, local Republican politicians like Brad Myhre, the mayor of Frenchtown, N.J., and Leonard Lance, a former congressman, mingled with a former Yankees star, Mark Teixeira, who posed for a photo with Mr. Kean.

A reporter for The New York Times was blocked at the door by Mr. Kean’s spokesman, Harrison Neely, who claimed that the event was private and that the media was not welcome. Hours later, however, he acknowledged that at least one reporter, Liz Elkind of Fox News, had been invited in.

Still hoping to talk to Mr. Johnson — or perhaps even Mr. Kean — on the way out, the Times reporter waited in a car in the parking lot.

That’s when things got weird.

A sergeant from the local police department in Washington Township appeared on the scene. Someone apparently had called the police from inside the club to report that there was a trespasser — this reporter — on the premises. (This despite the fact that New Jersey State Police troopers were stationed outside the country club, as was Mr. Johnson’s security detail.)

The officer, Sgt. Dallas Overko, amiably assessed the situation. He seemed somewhat confounded by the call.

“I didn’t know it was just a nice little reporter waiting for an interview,” Sergeant Overko said.

He headed inside to figure out what was going on and then returned a few minutes later to say that it was OK to remain in the parking lot.

“I guess there were some things lost in communication,” Sergeant Overko said.

Mr. Kean, the son of a former New Jersey governor, has held no in-person town hall events during his two terms in New Jersey’s Seventh District. In Washington, he has been known to forgo the normal practice of answering reporters’ questions when walking around the Capitol — even when it gets awkward

When he returned to Washington, on June 30, after his absence, Mr. Kean explained in a floor speech that he had been hospitalized for depression. He said that he was recovering and ready to return to work and to the campaign trail in New Jersey.

“I am a private person by nature,” Mr. Kean said in his speech.

In the weeks since, he has not publicly answered questions about his treatment. Politico reportedly got him on the phone earlier this month and asked about how he had signed off on personal stock transactions during his absence, eliciting some rare quotes from the congressman. (Mr. Kean said that he had no involvement in stock transactions made by his financial advisers.) Mr. Neely, his spokesman, has declined The Times’s many requests for an interview.

After Mr. Kean returned to work in Washington, Mr. Johnson said that he wished the New Jersey Republican had shared details about his health condition more promptly.

The speaker reiterated that position on Friday in a brief interview outside the fund-raising event after a Times reporter flagged him down from the parking lot.

“You know, if it were me, I would have done it a little sooner,” said Mr. Johnson, who has represented Louisiana in the House since 2017. “What he was dealing with affects many millions of Americans,” he added, “so I think people understand that.”

As for Mr. Kean’s refusal to talk to most members of the media, and the unusual police intervention on Friday, Mr. Johnson said that he encouraged his members to be transparent, but that every campaign had a “different flavor.”

“There are lots of campaigns that handle things differently across the country,” he said, noting that he was in the middle of a 30-day barnstorming tour across the country in support of Republican members.

The Times did not spot Mr. Kean leaving the event, and Mr. Neely said that he would have no comment.