As the self-styled “America’s Presidential Historian,” Barry H. Landau was a regular network guest, wrote a book on dining at the White House and claimed Bill Clinton once came with him to the vet when his dog got sick.

Landau spoke authoritatively on White House ceremony and glamour, expertise he said he gleaned from “serving” nine presidents and amassing one of the largest collections of presidential inaugural memorabilia. Perhaps nothing symbolized his supposed access to the powerful as much as one of his prize collectibles: an original key to the White House.

That carefully crafted public image came crashing down this month when Landau, 63, of New York, was charged with stealing historic documents from the Maryland Historical Society that prosecutors value at $6 million. At the same time, it’s beginning to look like many of Landau’s accounts of his exploits may have been wildly exaggerated.

Landau and an associate are accused of taking 60 documents, including some signed by Abraham Lincoln, inaugural ball invitations and a Washington Monument commemoration.

On Tuesday, Baltimore prosecutor Tracy Varda said in a detention hearing that authorities suspect the pair has been swiping such bits of history for about a year. She said that police found documents from the National Archives, Connecticut Historical Society and Vassar College in a locker linked to the two and that there is evidence Landau sold stolen documents for $35,000 to a dealer. And she said Landau’s associate may have ripped up historic papers and flushed them down a toilet before his arrest.

Landau’s alleged actions “show he has zero respect for the history and for this country,” Varda said.

Landau’s attorney called the charges “tenuous and circumstantial.”

“There were no documents recovered on Mr. Landau’s person. He was not seen removing documents. There was nothing found in his car,” Steven D. Silverman said. “If the case were tried today based on that evidence, it would be a slam dunk not guilty.”

Silverman declined to address the accusations of exaggeration or anything else beyond the criminal case. He said Landau would not comment.

As the criminal investigation grows, so do questions about whether Landau really is who he said he was.

Landau, who started his career as a New York publicist and published “The President’s Table” in 2007, has been profiled in The Washington Post and became a go-to commentator for CNN and NBC’s “Today Show” by sprinkling history with anecdotes of Washington elites. Landau’s Web site displays photos of him with five presidents, but the depth of those connections is unclear.

Landau told interviewers that he was a protocol officer under President Gerald R. Ford and that he once traveled to Moscow with President Richard M. Nixon. Libraries for the presidents said they could not find records of Landau in those roles.

Landau, who sports a beard and used to appear at events with his poodle, cuts a colorful figure: Actor William Baldwin has called him a “diva” of presidential history. Landau said Jacqueline Kennedy once suggested in a letter that he be the “Minister of Inaugurations” for the White House.

But even as he told engaging stories of presidents, he left a trail of suspicion.

Presidential memorabilia buff Robert Fratkin recalled an interaction with Landau from about a decade ago. Fratkin said Landau wanted to buy Teddy Roosevelt-era memorabilia from him and offered high-end Davidoff cigars as a deal sweetener.

“Barry always struck me as being a little too clever for his own good. . . . He’s great at dropping names. He told me: ‘I’ve got the Davidoff account. Do you want a box?’ ” said Fratkin. “Finally, I got three stale, crumbly cigars. I decided he wasn’t someone I wanted to deal with.”

The arrest

Landau and Jason Savedoff, 24, who is alleged to be an accomplice, arrived at the Maryland Historical Society bearing cupcakes July 9. Police were called after a staff member saw Savedoff tuck a document into a portfolio and walk out, according to court papers.

Varda, the prosecutor, said Tuesday that investigators found what they think were “little pieces” of documents floating in a historical society toilet. Police discovered Savedoff locked in a bathroom, according to court records.

A police officer later found 60 documents in Savedoff’s laptop case in a locker, court papers say. Some were signed out under Landau’s name. The pair were charged with stealing documents from the Maryland Historical Society with a value of more than $100,000. They have not been charged in any additional thefts, including those outlined in court Tuesday.

Savedoff’s attorneys did not return repeated calls for comment.

Varda said that investigators think Landau sold original speeches from the Franklin D. Roosevelt Presidential Library and Museum to a New York dealer and that they found a Benjamin Franklin letter belonging to the New-York Historical Society in his apartment. Other libraries are reviewing their records, Varda said.

The Historical Society of Pennsylvania in Philadelphia is among them. The pair made 17 trips to the society in six months, officials there said.

“When the news of the arrests came out, we knew them straight away,” said Kim Sajet, president of the society.

She said Landau and Savedoff, who visited in May, were an odd couple: Landau seemed scholarly, but Savedoff filled out forms sloppily. Sajet said authorities told her that they are looking into whether the pair is linked to a George Washington letter that had been missing from the society.

Landau’s visits have raised concerns on other occasions. Bob Currie, husband of Clinton’s former personal secretary, Betty Currie, said Landau called in 2009 and offered to organize their collection of Clinton memorabilia.

The Curries declined but invited him to stay at their St. Mary’s County home. Currie said Landau was charming and brought a souvenir plate. After he left, Currie said, the couple couldn’t find a book of signed speeches by the former president. A search didn’t turn it up. Eventually, they confronted Landau.

“He said, ‘I didn’t take it,’ ” Currie said referring to Landau.

‘Off and running’

The way Landau tells it, his interest in the presidency began at 10, when he met Dwight D. Eisenhower at LaGuardia Airport. Landau wrote the president a letter that evening and later visited the White House, according to an account in his book.

“I was off and running,” he wrote.

As a publicist, Landau bridged the world of entertainment and politics. Photos on his Web site show him with actors Al Pacino and Katie Holmes and historian Michael Beschloss. The release of “The President’s Table” increased his visibility.

Other details about his life are hazy. An attorney for Landau said he has been “self-employed” for 15 years. His Web site lists him as president of his multimedia company.

“He is a very curious kind of guy,” Larry Bird, a curator at the National Museum of American History, told The Post in 2005. “He sort of lives the life that he collects or aspires to collect, that sort of axis that spins between Washington, New York and Hollywood.”

Credibility issues

Over the years, Landau has highlighted his White House connections in media interviews, but initial checks cast doubt on some of his statements.

In 2001, Landau told the New York Times that he had been a White House fellow during President Lyndon B. Johnson’s administration, but his name does not appear in a publication that lists fellows from that period, a spokeswoman for the Johnson presidential library said.

In 2009, Landau told the Associated Press that he had been an assistant chief of protocol for Ford. Stacy Davis, an archivist with Ford’s presidential library, said there was no record of Landau having served in that capacity. The library does have a record of Landau attending a Ford presidential dinner in 1976.

In a July 4 interview posted on CNN’s Web site, Landau said he accompanied Nixon to Moscow. Landau’s name does not appear in a passenger manifest or a log of the president’s daily activities, an archivist with the Nixon presidential library said.

And in a Post profile in 2005, Landau said Laura Bush consulted with him at the 2004 Republican National Convention about her husband’s second inauguration. After the piece ran, Bush officials called The Post and said the meeting never occurred, said former Post reporter Timothy Dwyer, who wrote the profile.

Still, others said Landau was well-connected. Actor Brian Dennehy told The Post in 2005 that Landau “is always good about providing liaison with the White House.”

Landau burst onto the national scene in 1979, when he said on ABC’s “20/20” program that Hamilton Jordan, President Jimmy Carter’s chief of staff, asked him where to get cocaine at New York’s Studio 54 nightclub. Club owner Steve Rubell and a drug dealer alleged Jordan had sniffed cocaine on the same night.

A special federal grand jury concluded there was insufficient evidence to support the allegations. The Post reported at the time that the prosecutor expressed doubts about Landau’s “overall credibility.”

Staff writer Roxanne Roberts and staff researcher Jennifer Jenkins contributed to this report.