Selena Gomez’s lawyer has hit back at a lawsuit accusing the singer of wrongdoing over her mental health startup Wondermind.

The 34-year-old singer and Only Murders in the Building star was sued alongside her mother and Wondermind co-founder Mandy Teefey, 50, former business partner Daniella Pierson, 31, and the company itself in Delaware federal court last week.

The plaintiffs claim they were misled before investing nearly $US1.2 million ($A1.7 million) in Wondermind in 2022.

Among the alleged misrepresentations were that Gomez, 34, would be “actively building the company as its head of marketing”, that Pierson was a “$US200 million ($A282 million) executive” who had already secured partnerships, and that a “full slate of revenue-generating initiatives” had begun.

“Gomez purported to sign a contract obligating her to perform and then ignored it. The partnerships did not exist. The initiatives never materialised. The app was never built,” the lawsuit says.

“For three years, while the company quietly collapsed around them, not one of its founders, officers, or directors said a word to the investors whose money was funding the collapse.”

They allege Gomez’s “abject dereliction of her duties” has left the company in a “state of financial calamity”.

Gomez’s lawyer Mathew S Rosengart branded the allegations “completely meritless” and promised to fight to have them dismissed.

“The allegations that Selena Gomez engaged in any way whatsoever in any purported ‘fraud’ or other wrongdoing are completely meritless, both factually and legally,” he told Page Six.

Rosengart said Gomez – who married producer Benny Blanco almost a year ago –  would “vigorously defend these false allegations”. He said her legal team was “indeed filing a motion to dismiss the baseless claims”.

The case was brought by Wondermind SRS 44 LLC and Bespoke Wondermind LLC, which allege they were given a misleading picture of the business when they invested in September 2022. They say learned there were problems from a media article that included allegations from anonymous former employees claiming Teefey was unfit to serve as CEO.

According to the complaint, the investors claim they were led to believe Wondermind “had the infrastructure, leadership, and resources necessary for the company to launch into a profitable, one-of-its-kind mental health and wellness platform”.

Wondermind SRS 44 LLC and Bespoke Wondermind LLC are seeking the return of their investments as well as damages, costs and lawyers’ fees.

Forbes reported last May that the company was struggling to pay its employees. A source told People magazine then than Gomez was quick to act.

“Selena has invested millions of dollars over the years into Wondermind to support her mother and their shared passion for mental health, including when she was alerted about the most recent financial setback, and immediately invested more money as she’s not involved in the day-to-day operations,” they said.

“To invest in the future of the company, Mandy has chosen to take the lead here with a personal loan to invest in the future of the company.”

Gomez set up Wondermind after going public with her own mental health struggles, including with bipolar disorder.

The legal dispute comes as she continues filming the sixth season of Only Murders in the Building, the hit mystery comedy in which she plays Mabel Mora alongside Steve Martin and Martin Short.

Production has moved to London for the forthcoming season, which follows the death of podcaster Cinda Canning, played by Tina Fey.

Gomez first rose to fame as Alex Russo in Disney Channel series Wizards of Waverly Place. She went on to have a music career, with hits such as Come and Get It, Hands to Myself, Lose You to Love Me and Calm Down.

Her businesses have also become an increasingly prominent part of her public career, particularly cosmetics company Rare Beauty, which she founded in 2020.

Gomez is one of the most-followed women in the world on social media, with more than 500 million followers, and an estimated net worth of nearly $US1 billion.

-with AAP