The offer was enticing to high school principal Kathleen Mahar. The producer of a TV program called "In Focus" said he wanted to feature her school, Archbishop Spalding High in Anne Arundel County, Maryland, in a short segment about stellar educational institutions. The program, he told her last month, would be hosted by actor Martin Sheen and shown on PBS stations.

One more thing, said the producer: In Focus charged a pre-production fee of $23,400, plus $3,500 for "location" shooting.

Mahar's interest turned to confusion - and then suspicion. She passed. "I thought, 'Martin Sheen has a TV show?'" she said. "I wasn't aware 'West Wing' was still on."

In Focus appears to be a relatively recent entry in the field of interstitial videos - short pieces, typically three to five minutes, that bridge the gap on-air between longer programs. Companies such as In Focus approach businesses, trade associations and nonprofit organizations, offering to produce flattering segments. The short films are intended for public television stations, the companies say.

Another attraction is the participation of a celebrity or TV news star as the host of the segment.

But rather than a news program, the segments the companies produce are more like infomercials - commercials that mimic the look of documentaries and TV reports. In Focus promises in its contracts to give "participant companies" control over the material it shoots, something an independent news organization would not permit. The subject of the video is often asked to pay upwards of $20,000.

PBS says it has no business relationship with the program or the company, which is based in Boca Raton, Fla. The public-broadcasting organization has warned businesses and nonprofit groups for years about producers who claim otherwise. In fact, public stations and PBS follow guidelines that prohibit them from airing programs paid for by the subject of the program. And federal regulations require stations and producers to tell viewers when a company or organization has paid to appear in a program.

A disclaimer on PBS's website reads, "PBS wishes to clarify that it is not associated with and does not endorse, distribute programming for, review underwriting for or otherwise have any business relationship" with more than three dozen such programs and production companies, including In Focus.

"We are concerned about what we're seeing," said Jan McNamara, a PBS spokeswoman. "We're actively looking into what steps we can take."

In Focus refers to itself as "In Focus Martin Sheen PBS, Public Television (TV) Show" and "Martin Sheen on PBS (Public Broadcasting)" on some of its Web pages. It promotes the program via URLs such as MartinSheenPBS.com, InFocusPBS.com and InFocusMartinSheenPBS.biz. Its Facebook page states, "In Focus is hosted by Martin Sheen and airs on PBS," and its YouTube page bears this description: "In Focus with Martin Sheen airs on Public Television and PBS member affiliate stations."

Company spokesman Joe Salerno said in an interview: "We've never claimed to work with PBS. We don't work with them." He also said the program has yet to air on a public TV station. "We haven't distributed it yet," he said. "We're still in the production process. We should be distributing it out in the next 30 to 60 days."

In contract documents, In Focus tells participants that each finished video "will be distributed" to "public Television stations in all 50 states," with potential "estimated viewership and reach for one year (of) 60 million households."

But it adds that the broadcasts are "at each station's discretion," meaning that the company has no control over whether the programs are actually broadcast.

Salerno said that In Focus has worked with about 100 clients in the past six months and that "not one client has an issue with us." He declined to identify any of the clients.

The company also offers to create 30- or 60-second commercials for its clients that are separate from the educational videos hosted by Sheen. It tells prospective clients in a "production agreement and contract" that "Your segment will be broadcast fifty (50) times in primetime in the cities of your choice via MSNBC, CNBC, CNN or an equivalent network of your choice." The agreement doesn't say that clients are responsible for the cost of this airtime, which in some instances can run into the millions of dollars.

In Focus' main website carries a schedule that appears to list times, dates and networks of broadcasts of In Focus's work. Among its dozens of entries are such cable networks as CNBC and the Discovery Health Channel. But spokespersons for both networks say they have no record of having aired any of the Sheen videos.

Salerno said the airing schedule refers to the 30- and 60-second commercials that In Focus created for some of its clients, not to the longer Sheen programs.

Sheen's participation in the segments is limited to making a few general comments at the beginning and end of the videos. He recites a brief introduction about a topic, such as health care, education or environmentalism, without mentioning a specific company or product. He does not appear in the recorded segments featuring the companies and organizations that follow his introduction. As the segments end, he reappears on camera to thank viewers for watching. Sheen reads his introductions and farewells from what appears to be an elegant theater lobby, with a grand staircase in the background. His segments seem to have been produced in quick succession; the actor wears the same suit, shirt and tie in multiple segments.

Calls to Sheen's representatives were not returned.

The Museum of Spanish Colonial Art in Santa Fe, N.M., last month signed an agreement with In Focus to be in one of its videos with Sheen, said Donna Pedace, its executive director. Production hasn't started yet, but Pedace said she was impressed by Sheen's involvement and the chance to appear on public TV stations across the country.

"We're a small nonprofit," she said, "and I made a calculated decision that if they're able to get even a percentage of the exposure they described, it would be far more than we would be able to do on our own."

"I'm certainly not a TV or broadcast person, so I'm not sure exactly what you'd call this type of program," Pedace said. "But it certainly seems attractive to us."