Late Singer Selena Quintanilla's Sister Sues Shein Over Clothing Line

3/13 -- 6:24 AM PT -- A spokesperson for SHEIN tells TMZ ... "When we were made aware that the products in question were being sold on SHEIN Marketplace by third-party sellers, we immediately removed the listings from our platform and launched an investigation."

They continue, "SHEIN requires sellers to comply with company policy and certify that their products do not infringe third-party intellectual property. We take all claims of infringement seriously and act swiftly when valid complaints are raised by IP rights holders. We continue to invest in and strengthen our processes to ensure partners adhere to our strict policies."

Suzette Quintanilla -- the sister of late music icon Selena Quintanilla-Perez -- is suing Shein, claiming the company has been splashing her famous sister's face all over clothes sold on its website without any permission ... TMZ has learned.

In court papers, obtained by TMZ, Suzette says Shein used Selena's likeness all over shirts and other clothing without being given -- or even seeking -- authorization.

According to the docs, Suzette and the family's music company, Q-Productions, owns and meticulously controls Selena's image, so they issued Shein a cease and desist letter around August 1, 2025.

But the papers allege Shein ignored their request and just kept on peddling the unauthorized merch. Now, Suzette is suing over it, asking the judge to stop the company in its tracks and seeking all the profits Shein garnered from Selena's likeness ... plus other damages.

The suit includes exhibits of t-shirts allegedly posted on the Shein website, which featured images of Selena's face on them.

As you know ... Selena was one of the most influential Latin artists of her time before her tragic death in 1995. The singer-songwriter was shot and killed by the woman who was manager of Selena's boutiques -- Yolanda Saldívar.

Selena confronted Yolanda over a financial dispute, at which point Yolanda shot and fatally wounded Selena, who later died at the hospital. She was 23.

We've reached out to Shein ... so far, no word back.