A lawsuit filed on Fridayaccuses the renowned Washington glass artist Dale Chihulyof passing off the work of another man as his own for 15 years.

The suit, filed by the lawyers of Michael Moi in King County Superior Court and the U.S. District Court for Western Washington, claims the prolific decorator of botanical gardens has been involved in a myriad of clandestine painting sessions with Moi, but has never compensated him or given him credit for his efforts, despite the artists promises otherwise.

The truth behind the creation of his paintings has been intentionally hidden, Moi claims.

In a press release sent to HuffPost, Chihulys camp strongly refutes Mois claims, dubbing the lawsuit baseless.

The statement, sent on Friday from Chihulys studio headquarters in Seattle, claims the studio hired Moi as handyman forvarious cleaning, repairing and small construction projects over the years.

Moi also alleges possession of Chihulys private documents, including medical papers and personal letters, that would be substantively uncomfortable if released to the public, the statement adds. In February, the statement continues, Moi asked for $21 million, threatening to publicly file a lawsuit if his demand for money was not met. Earlier this month, when Chihuly had not agreed to pay him, Moi served Chihulys legal counsel with a state court complaint.

Chihuly Inc.asserts that it has allowed Mois claims to go public rather than accede to Mr. Mois ultimatum, characterizing the demands as nothing more than an ugly and reprehensible display of opportunism and exploitation motivated by a desire to disclose private information, specifically about Chihulys mental health, a topic of a recent Associated Press interview.

Chihuly told the AP he has been dealing with bouts of depression since his 20s, and, at 75 years old, suffers from bipolar disorder.Im usually either up or down, he said. I dont have neutral very much. When Im up Im usually working on several projects. A lot of times its about a six-month period. When Im down, I kind of go in hibernation.

Mois lawsuit demands credit for joint work a large volume of paintings he says were created at Chihulys Boathouse in Washington, some involving blow torches and plexiglass as well as the revenues derived from their sale.

Moi never held the position of painting assistant, the company counters, while acknowledging that Chihuly does not work alone he uses studio assistants to execute his vision, particularly his large, glass-blown sculptures that often resemble alien sea creatures or Seussian shrubbery. (A few anonymous reviewers of Chihuly Studio on Glassdoor claim to have experienced a less-than-ideal working environment.)

Chihuly has been a part of court cases concerning his art before. In 2006, he sued two fellow glass-blowers, one of whom was a longtime collaborator, for copyright infringement, claiming they had purposefully mimicked his signature style. (The case against one of them, Bryan Rubino, was settled.)

Chihulys work is currently on view in shows at the New York Botanical Garden, as well as Arkansas Crystal Bridges museum. Its also included in more permanent displays in venues across the country.