NEW YORK (Reuters) — The friendship between television news anchor Maria Bartiromo and former Citigroup executive Todd Thomson raises questions about ethical boundaries between reporters and their sources, experts said.Thomson found himself out of a job after spending $5 million of Citigroup’s money to sponsor a show hosted in part by CNBC news anchor Bartiromo, the Wall Street Journal reported last week.

The report said Citigroup executives were also irked by Thomson’s flying Bartiromo (pictured), called “the Money Honey” by tabloid newspapers, to New York from Beijing, China in a Citigroup corporate jet.

A spokesman for financial news network CNBC said Bartiromo’s plane trip had been approved by her managers, and that CNBC paid Citigroup for her flight. He declined to elaborate on further questions regarding Bartiromo and Thomson.

This is not the first time Bartiromo has been at the centre of controversy.

In May, she roiled stock and bond markets after discussing in a broadcast a conversation she had with Federal Reserve Chairman Ben Bernanke at the White House Correspondents’ Association’s annual dinner. Many reporters understand the dinner to be off the record. Personal relationships are crucial to reporters who vie to get stories first. But friendships that are too close can raise questions about objectivity, said Bob Steele, senior ethics faculty member at the Poynter Institute, a training and research centre for journalists.

“Was there any personal connection with Mr. Thomson that could raise concerns about competing loyalties? It’s a reasonable question to ask, and important for her to answer in a meaningful way,” Steele said.

Flying on Citigroup’s corporate jet could be seen as too close a relationship, even if the network paid for the flight, said Joe Bernt, professor of journalism at the E.W. Scripps School of Journalism at Ohio University.

Experts said one could argue that the plane ride gave Bartiromo access to a powerful figure at Citigroup, much the way White House reporters may have access to the US president by flying on Air Force One.

But the analogy is not perfect, said Deni Elliott, who teaches media ethics at the University of South Florida in St. Petersburg. More than one reporter typically flies on Air Force One at the same time, and it may be the only time that reporters can get access to a president, Elliott said.

Citigroup’s $5 million sponsorship of a Sundance Channel show that Bartiromo was to host with other personalities is also nettlesome if Bartiromo and Thomson are friends, said Pamela Luecke, professor of business journalism at Washington and Lee University in Lexington, Virginia.

Bartiromo is no longer scheduled to appear on the Sundance Channel show.