Pop art master Jasper Johns's long-time assistant James Meyer was arrested Wednesday for stealing at least 22 works from his employer.

After 27 years of service to Johns, Meyer was charged with pilfering and then selling artworks through an unnamed New York gallery for $6.5 million. He fabricated a tale that the artworks were gifts from Johns, and that they would appear in the artist's catalogue raisonne.

Meyer kept $3.4 million in the sale proceeds, and buyers were told to keep the sales private for at least 8 years, according to the indictment.

The indictment says Meyer “maintained a file drawer containing pieces of art that were not yet completed,” and that he started removing the art between 2006 and 2012.

Meyer pleaded not guilty to federal charges in a Hartford, Conn., courtroom, and was released on an unsecured $250,000 bond. He faces charges of one count of interstate transportation of stolen property, which carries a maximum sentence of 10 years in prison, and one count of wire fraud, which carries a maximum sentence of 20 years in prison.