This post has been updated throughout.

Federal prosecutors outlined a sweeping criminal complaint against Sen. John Sampson this morning, accusing him of embezzling $440,000 from escrow accounts over more than a decade and accepting a $188,500 “loan” from a business associate later related to fraud.

In the latest corruption scandal to hit Albany, then Brooklyn Democrat was taken into custody this morning by federal agents in connection to the embezzlement scheme that began in 1998 from the escrow accounts involving multiple Brooklyn properties

And for an only-in-Albany twist, the unsealed complaint today indicates that Sampson had a mole in the U.S. Attorney’s Office supplying him with information on possible cooperating witnesses who was later fired.

His effort to find more information on the investigation and possible cooperating witnesses began in July 2011, when the unnamed associate was arrested for fraud and asking the person to withhold documentation in the case, court records show.

According to the complaint, Sampson went as far as trying to identify those cooperating with investigators so he could “take them out.”

Sampson, first elected to the Senate in 1996, was the leader of the Senate Democrats until 2011, when he was ousted by now-Senate Minority Leader Andrea Stewart-Cousins.

Court documents also show that Sampson in an interview with federal agents admitted he sought information on the mortgage fraud case, but claimed it was only public information. When asked why he sought readily available public information on a court case when he was an attorney himself, Sampson claimed he was not “good” with computers.

When law enforcement officials interviewing the lawmaker said he was lying, Sampson responded, “Not everything I told you was false.”

Sampson is the third sitting state lawmaker this year to be arrested on corruption charges. The arrest comes after Sen. Malcolm Smith, a Queens Democrat, is accused to have sought to bribe his way onto the New York City mayoral GOP ballot.

Assemblyman Eric Stevenson was arrested that same week in an unrelated bribery scandal and accused of writing favorable legislation for the development of adult day care centers.

“Today John Sampson has been added to the list of recently indicted New York elected officials,” said FBI Assistant Director George Venizelos in a statement. “We could view this as an achievement for the FBI and federal prosecutors. But we share what may well be the concern of many New Yorkers that ‘incumbent’ and ‘defendant’ cannot be accepted as interchangeable. Elected officials are referred to as ‘public servants,’ and that should not be confused with ‘self-serving.’ The people of New York have a right to demand, at a bare minimum, that their elected representatives obey the law.”

He is being charged with obstruction of justice, two counts of witness tampering, two counts of embezzlement and making false statements.

Sampson was made leader of the conference in 2009 following the bruising leadership coup in the chamber.

Sampson Criminal Complaint by Nick Reisman