The financial records of a highly regarded Philadelphia charter school launched in 1999 by a well-known local education activist have been subpoenaed by federal authorities, according to its founder.

A federal grand jury subpoenaed five years of financial records from the Mathematics, Civics and Sciences Charter School in Center City last week, Veronica Joyner said yesterday.

"We have done nothing wrong," said Joyner, a former teacher who founded the school, at Broad and Buttonwood streets.

"We are not accused of anything," she added. "They explained to us that there is no wrongdoing. They just want to look at the records."

Agents are "looking at a number of charter schools, they told our attorneys," said Joyner, also founder of the advocacy group Parents United for Better Schools.

On March 22, a federal agent delivered the subpoena to the school's certified public accountant, Rhonda Sharif, according to a source familiar with the investigation.

The school's attorney, Matthew H. Haverstick, could not be reached for comment.

It was not immediately clear whether and how the federal subpoena is related to reports last year of a wide-ranging federal investigation into both financial irregularities and possible conflicts of interest at as many as five charter schools in Philadelphia.

Last summer, the Daily News reported that federal agents retrieved records from the Community Academy of Philadelphia Charter School, on Erie Avenue near J Street, in Juniata, and from Fairhill Community High School, 4th Street near Somerset, in Fairhill.

Shortly before that, two leaders of the Philadelphia Academy Charter School pleaded guilty in federal court to stealing funds from the school.

In May 2009, Brien N. Gardiner, founder of that school, committed suicide.

The Mathematics, Civics and Sciences Charter School claims on its Web site that it is one of the largest charter schools in the state with nearly 1,000 students in grades one through 12. It also says it has been cited as one of the top 10 schools in Philadelphia.