A former official with the Washington Teachers Union has become the second person indicted on charges stemming from a money laundering scandal.

According to the U.S. Attorney's Office, Michael Martin was charged Wednesday with conspiracy and money laundering. Martin was an associate of former union president Barbara Bullock and her assistant, Gwendolyn Hemphill.

Court documents say Bullock, Hemphill and union treasurer James Baxter wrote union checks totaling $483,543 to a fictitious business known as Expressions Unlimited. Martin allegedly paid back most of the money out of a bank account he set up.

Martin's indictment comes after Bullock's former chauffeur pleaded guilty in February to federal money laundering charges. Now, Leroy Holmes is cooperating with several agencies in the investigation that could send several others to prison on related charges.

Holmes was charged with cashing checks worth more than $1.2 million. He told investigators he would cash the checks, take out his salary and return the excess cash to Hemphill, or sometimes deposit it to Bullock's personal account.

The American Federation of Teachers has taken over the WTU and filed a civil lawsuit seeking $5 million in restitution on behalf of its 5,000 members. The AFT is also returning more than $700,000 in dues overcharges collected from members last summer by the former leadership.