The New York Times has sued OpenAI and Microsoft for the unauthorized use of its articles to train their artificial intelligence programs.

The leading US newspaper filed the lawsuit with a US court on Wednesday. OpenAI is the developer of the AI chatbot ChatGPT, and Microsoft is its business partner.

The complaint says the two firms unlawfully copied and used the paper's "uniquely valuable works," causing "billions of dollars in statutory and actual damages."

The New York Times updated its terms of service in August, fundamentally banning the use of its articles and photos to train AI systems.

The newspaper says this is the first time that a major US media outlet has sued AI developers for copyright infringement.

AI developers need to use media articles and other online data to improve the accuracy of their AI models. But critics say such use of web content could constitute copyright infringement.

Meanwhile, a major German media firm, Axel Springer, announced a business tie-up with OpenAI earlier this month.