HARRISBURG, Pa. — A freshman state lawmaker from Philadelphia secretly pleaded guilty six months ago to a felony charge that she helped a member of a politically connected family embezzle money from a health clinic, a federal court document unsealed Wednesday shows.

The document appeared on the court docket of Democratic Rep. Leslie Acosta, who was accused of aiding in the theft of hundreds of thousands of dollars from the publicly funded Philadelphia clinic where she once worked.

Acosta pleaded guilty March 4 in U.S. District Court to a felony charge of conspiracy to commit money laundering. But the plea agreement was placed under seal at that time.

The case against Acosta was brought last November, also under seal, and did not come to light until a report last week by The Philadelphia Inquirer. Even Democratic Party officials and lawmakers who have known Acosta for years said they did not know about the case against her until the news story appeared.

The reasons for the secrecy have not been made entirely clear.

Acosta’s lawyer Christopher Warren said Wednesday the judge had good reasons for sealing the records. But he said if he commented further it could compromise the ability of clinic board president Renee Tartaglione, who is alleged to have received all the pilfered money, to get a fair trial.

In a court conference last week on Tartaglione’s case, a federal prosecutor said the guilty pleas of those cooperating in the case had been sealed because witnesses had expressed concern over their security, the Inquirer reported. The prosecutor did not identify any of those cooperating, but one is believed to be Acosta, based on the information available in the case.

Like Tartaglione, Acosta is also part of a politically connected family, the daughter of a former state lawmaker and Democratic Party ward leader in Philadelphia.

At the time of the alleged embezzlement, Acosta worked at the Juniata Community Mental Health Clinic, which serves Medicaid patients. Acosta’s role in the alleged scheme was outlined as cashing fraudulent checks made out to her from the clinic and returning the money to Tartaglione.

Two other senior employees also have pleaded guilty in the scheme, according to Tartaglione’s defense lawyers, and are believed to be cooperating with the government. Acosta’s mother, Sandy Acosta, is one of the other employees charged in the scheme and has entered a plea, but that remains under seal.

Tartaglione, who started the clinic along with her husband, is the sister of a state senator who once chaired the Pennsylvania Democratic Party. She was charged in January with embezzling hundreds of thousands of dollars for her personal benefit. She has pleaded not guilty, and her trial is set to begin Nov. 7.

In court filings last week, Tartaglione’s lawyer, William DeStefano, wrote that the government had taken “great pains” to hide the identities of three people who had pleaded guilty in the case, although he said he knew their identities. He suggested the three were conspiring to blame their wrongdoing on Tartaglione.

Acosta’s charging document was quietly unsealed in March after the judge approved her plea agreement, but all details of that plea agreement remained under seal until Wednesday.

Acosta is running unopposed for a second term in the Nov. 8 election.

Warren said Acosta will not resign, despite Democratic Party pressure to step down and take her name off the ballot so the party can substitute another candidate on the ballot.

Under state law, a convicted felon must leave office upon sentencing.

At least 10 current or former state lawmakers, all Democrats, have been charged with various unrelated charges since the beginning of 2014.