The FBI is investigating relationships between members of the Prince George's County Council and developers who do business with the county, according to an official familiar with the investigation and a company that has been contacted by agents.

"The FBI has been involved for several weeks," said the official, who spoke on condition of anonymity because of confidentiality requirements.

FBI agents are planning to meet Monday with Kenneth H. Michael, an influential developer who has done extensive commercial and residential work in Prince George's. Michael did not return phone calls seeking comment yesterday, but Dennis Brownlee, a vice president of his company, said that agents had been trying to reach Michael for more than a week to arrange a meeting.

Brownlee said he did not know specifics about what the FBI is interested in knowing, except that it is "something associated with the County Council. We don't know what, we don't know who. But when they call, you answer."

In more recent days, the FBI has begun an unrelated investigation of Prince George's schools chief Andre J. Hornsby and his dealings with some educational vendors, said an official familiar with that investigation. The FBI's interest in Hornsby follows an inquiry by the Maryland state prosecutor's office into his acceptance of a 10-day trip to South Africa last year from a company that does business with the school system.

The precise substance and scope of the bureau's investigation into the County Council could not be learned yesterday. Six of the nine council members -- Marilynn Bland (Clinton), Samuel H. Dean (Mitchellville), Thomas E. Dernoga (Laurel), Camille Exum (Seat Pleasant), David Harrington (Bladensburg) and Thomas R. Hendershot (New Carrollton), all Democrats -- said they had no knowledge of the FBI probe and had not been contacted by agents.

Council Chairman Tony Knotts (D-Temple Hills) did not return calls, and member Douglas J.J. Peters (D-Bowie) could not be reached by phone. One council seat is currently vacant.

Some council members have, in recent months, increasingly expressed concern over the pace of residential development in Prince George's. Among the projects contributing was Karington, a $900 million planned community in Bowie headed up by the Michael Cos., of which Kenneth Michael is chairman of the board.

For several months this year, Bland, who represents much of the county's rapidly growing rural southern tier, placed a hold on new construction projects in her district, exercising a traditional privilege for council members. And a six-member voting bloc, which became known as the "Gang of Six," formed because its members were at odds with County Executive Jack B. Johnson (D) over development.

The six-member bloc consists of Dean, Dernoga, Exum, Harrington, Peters and Knotts .

Michael later donated $12,000, and another developer, Pat Ricker, gave $15,000 to a petition drive aimed at restructuring the council through a ballot issue. Some supporters of the measure, which voters rejected overwhelmingly last Tuesday, saw the Gang of Six as evidence that the council needed to be restructured.

The measure, known as Question H, would have added two at-large seats to the council. Proponents reasoned that at-large members would be less parochial in their view of development issues, while opponents argued that candidates running more costly countywide campaigns would be dependent on contributions from developers.

The official who confirmed the FBI investigation said yesterday that Michael's name and that of the group that organized the petition drive -- the county chapter of the Association of Community Organizations for Reform Now (ACORN) -- had surfaced in connection with the inquiry. It was unclear what role, if any, each party played in the matter under investigation, the official said.

Some members of the County Council complained to the developers after learning of their support for the measure.

"I did have a conversation with both Pat Ricker and Ken Michael, and I said I was disappointed that they had supported Question H," Harrington said. "I felt they didn't understand the magnitude of the question."

Jessica Lehman, head organizer for ACORN in the county, said contributions to the effort dried up soon after the developers' support was disclosed through campaign finance reports. "The council [majority] was clearly vehemently opposed to it, and that made it very difficult for anyone to give money," Lehman said. She said she had not been contacted by the FBI.

Ricker was unavailable for comment yesterday, but in an interview in August, he said he supported the ballot issue out of friendship for Hendershot, one of its chief sponsors, and not to neutralize the Gang of Six.

Meanwhile, Hornsby declined to comment yesterday on the FBI investigation into his conduct, which was first reported by the Baltimore Sun. His spokeswoman, Kelly Alexander, said he had not been contacted by federal agents. "I'm not aware of the [school] board or administration receiving any notification of any kind of investigation being conducted by any [federal] governmental organization," Alexander said.

Hornsby said in an interview last month that the Maryland state prosecutor's office had opened an inquiry into a 10-day trip to South Africa that he accepted last year from an educational software company that does business with the school district. Minnesota-based Plato Learning paid for Hornsby's trip in July 2003 when he was president of the National Alliance of Black School Educators.

He said he notified the school board of the trip before it hired him. Board members have confirmed that disclosure, but board Chairman Beatrice P. Tignor (Upper Marlboro) has said Hornsby did not mention that the company would pay for it.

In the same interview, Hornsby acknowledged that he was directly involved in the school system's purchase of nearly $1 million of software and other teaching tools from LeapFrog SchoolHouse, a company based in California. He said he did not disclose to the school board that he lives with Sienna Owens, who sells LeapFrog products, because Owens handles sales in Virginia and was not involved in the Prince George's transaction.

In the interview, Hornsby said the school system has been doing business with LeapFrog since 2002, but that spending on the company's software increased substantially since he arrived in the county just over a year ago. He said that in June, when a large number of purchases was made, the school system had federal Title I grant money that had to be spent quickly or returned. He added that he felt Leapfrog was the only vendor that could provide the software and equipment needed, including laptop computer-like machines that the county is using to teach reading to low-income kindergartners.

Leapfrog officials did not return calls seeking comment yesterday. Last month, a company spokesman said the transactions were handled by Maryland sales representative Debora Adam, not Owens, but that it would open an interval review as a precaution. The results of that review have not been disclosed.

School board member Judy Mickens-Murray (Upper Marlboro) said yesterday that she plans to ask Tignor to convene a meeting of the panel. "I think it's time for us to come together and have a discussion," she said. "We just have to figure out where we are and what's going on. The FBI inquiry is of concern."

Some board members, however, questioned the FBI's involvement. "I didn't think the allegations merited all of this," said board Vice Chairman Howard W. Stone Jr. (Mitchellville).

Board member Dean Sirjue (Bowie) said he was concerned that "this is politically motivated and some politicians in the county might have a personal agenda in going after Dr. Hornsby and [are] looking for every little incident to blow it up."

Staff writers Nancy Trejos, Paul Schwartzman and Allan Lengel and staff researcher Bobbye Pratt contributed to this report.