Estée Lauder announced it was seeking to have Brandon Truaxe removed as co-CEO of the skin-care company Deciem, following months of erratic online behavior and personnel decisions by the company founder.

In a statement this week, Estée Lauder said it was “deeply concerned” about material Truaxe posted on Deciem’s social media accounts, and that it would defend its rights as a minority investor.

“We can confirm that we have commenced legal action in this matter,” Estée Lauder told Cosmetics Business.

“We cannot comment further on this pending litigation at this time.”

Deciem, best known for its skin-care line The Ordinary, was founded in 2013 by Truaxe, a former computer programmer.

This January, Truaxe took control of the company’s social media accounts and began posting personal, sometimes rambling, messages, using the company’s platform to cut ties with collaborators and attack online commentators.

He also published emails from Estée Lauder executives. He fired co-CEO Nicola Kilner in February, then rehired her in July. Around the same time, chief financial officer Stephen Kaplan resigned after less than a year in the post.

On Monday, on the company’s Instagram account, Truaxe announced, “almost everyone at Deciem has been involved in major criminal activity, which includes financial crimes.” He referred to himself as a “soldier” and said Deciem would close all operations for “about two months.”

Estée Lauder is seeking Truaxe’s dismissal from Deciem’s board of directors and wants to bar him from hiring or firing employees and from issuing statements on the company’s social media accounts.

Deciem had hit $300 million in revenue, selling serums and acids that retail at around $10. But Truaxe’s social media postings prompted speculation about his mental health, and whether his behavior posed a threat to the company, or if it was instead savvy marketing.

The company employees about 800 people and has more than 20 stores globally.