Prince George’s County Council member Leslie Johnson, who is accused of concealing evidence in a sweeping corruption probe, is scheduled to appear in U.S. District Court in Maryland on May 4 for a plea hearing, according to a Tuesday court filing.

Johnson (D-Mitchellville), 59, and her husband, former county executive Jack B. Johnson (D), 61, were arrested in November as part of an investigation into whether public officials in the county accepted and solicited bribes.

Last week federal prosecutors in Maryland filed a criminal information charging Leslie Johnson with conspiracy to commit witness and evidence tampering, a legal step that means a defendant is likely to enter a guilty plea.

She was overheard on a wiretap on the day of her arrest conspiring with her husband to flush a $100,000 check from a developer down the toilet and hide $79,600 in her undergarments, court papers say.

Jack Johnson was indicted Feb. 14 on bribery charges, and prosecutors allege he accepted more than $200,000 from a developer in return for favors. He pleaded not guilty and said he will fight the charges.

The felony charge against Leslie Johnson deals only with her actions that November day. It does not accuse her of bribery.

Prosecutors said in court papers that Leslie Johnson's actions damaged the “evidence’s integrity and availability for use in the course of an ongoing federal Grand Jury investigation... and any subsequent federal criminal proceedings.”

The case against Leslie Johnson is part of a six-year corruption investigation that prosecutors say involves other county officials and business people. Authorities have said additional indictments are likely in coming weeks and months.

Leslie Johnson, a former administrative law judge who has been active in community groups, was elected to the council Nov. 2. If she is convicted of a felony, Johnson would have to step down from her council seat.

After the criminal charges, some residents and public officials pressured Leslie Johnson to resign, but she has retained her seat.

In December, the council took the unusual step of barring Johnson from sitting on committees, where dozens of key decisions are made. The council agreed she may attend committee meetings and vote on bills that come before the full nine-member body.