Donald Trump's frequent campaign events in Trump Tower are attracting scrutiny from New York City officials who want to know whether he is abiding by rules requiring the building's atrium to be open to the public.

The landmark tower's grand marble lobby is supposed to be open to visitors from 8 a.m. to 10 p.m. daily under an agreement that Trump struck with the city back in the late 1970s in return for the right to make the tower bigger.

City inspectors are examining whether people were barred from the space Tuesday for a Trump news conference, one of many campaign events the Republican has held in the atrium since announcing his campaign for the presidency there last June.

"We'll investigate whether the space was closed," said Buildings Department spokesman Joe Soldevere.

An executive and lawyer for the Trump Organization, Michael Cohen, insisted the atrium remained open.

"The property was never closed and I dispute any reports from anybody stating otherwise," he said.

An Associated Press reporter observed only credentialed media and building employees permitted to enter after being screened by U.S. Secret Service agents Tuesday as onlookers peered into the building from Fifth Avenue.

Trump has marked several of the biggest moments of his campaign in Trump Tower. He held celebratory news conferences in the skyscraper's atrium following his victories in the New York primary on April 19, multistate primaries on April 26 and the Indiana primary on May 3.

As one of a handful of privately owned public spaces in the city, the Trump Tower atrium can only be closed by the building owners for private events four times a year, city officials said, and only with the city's permission.

The city's planning and buildings departments told The Associated Press they could find no record in the past two years of Trump Organization officials seeking prior authorization to use the space for a private event.

Cohen wouldn't address previous use of the atrium for campaign events.

This isn't the first time city officials have confronted Trump over use of the public atrium. He was fined $4,000 in 2015 and $2,500 in 2006 for installing kiosks selling merchandise in the space.

Tourist David Miller, 38, of Columbus, Ohio, said he was disappointed he wasn't able to make it in to hear the presumptive Republican presidential nominee address his charitable giving to veterans' groups in a contentious news conference.

"I had really hoped to get inside and take a look and I may not be able to now," Miller said.