China’s national security authority has warned of risks in using “artificial intelligence relay services” that provide access to overseas AI models, highlighting concerns over data leaks, privacy breaches and unauthorised cross-border data transfers amid a thriving grey market for restricted foreign systems.

In a notice on its official WeChat account on Monday, the Ministry of State Security (MSS) described such services as intermediaries between local developers and AI providers, aggregating access to multiple domestic and overseas models through a single interface.

While relay platforms offer convenience, lower prices and access to foreign models otherwise unavailable in China, the ministry said some operators could pose data security risks.

The AI relay market includes both legitimate and unreliable operators, with some platforms operating “without proper qualification and with weak security controls, increasing the risk of privacy leaks and illicit data trading”, MSS said.

The warning comes as more Chinese developers turn to relay services to access leading US AI models such as Anthropic’s Claude or Microsoft-backed OpenAI’s GPT series, neither of which officially supports users in mainland China.

The ministry said some relay platforms retained user data on their servers without adequate encryption, creating risks that sensitive information could be leaked or sold.