China's top spy agency has warned Chinese students to be alert to the risk from foreign spies when studying abroad.
The warning from the Ministry of State Security comes amid a sweeping national security drive.
In a post on the ministry's WeChat account it told the story of a "real case" involving a Chinese graduate who, it claimed, had secured a place from a "top ranking" foreign university despite failing the Chinese college entrance exam in 2006.
It said the student, identified only by the surname Zhang, had been "severely punished" for his role in leaking Chinese scientific research after graduating.
The ministry did not say where Zhang had studied, but it said he had been responsible for liaising with Chinese students abroad and had done well in his studies, which brought him to the attention of a senior figure in the university.
This individual was then said to have put Zhang in touch with two people who turned out to be foreign spies and convinced him to provide intelligence on Chinese international students and other "sensitive information" in return for money.
The account said these spies had secured Zhang a job in a Chinese research institution in China, even though he did not have the correct credentials, and told him to appear to be helpful to his colleagues to collect information.
The State Security Ministry said Zhang had "squandered his promising future" by giving in to the foreign intelligence agency's "emotional manipulation and monetary temptation".
It warned the public to be alert to national security risks and "uncover the hidden motives behind various seemingly innocent interactions" while studying and travelling abroad.
In recent months the Chinese authorities have heightened their focus on risks to national security, with the state security ministry becoming more active on social media to warn of the threat from foreign spies.
Last year, State Security Minister Chen Yixin said the country must "proactively defend" against foreign spies to strengthen national security and the Communist Party's leadership.
A new counter-espionage law came into effect in July 2023, which expanded both the definition of spying and the investigative powers of national security agencies.
Although China and the United States recently pledged to boost academic exchanges as part of a wider effort to improve relations, Chinese students in America are still at risk of being caught up in the wider tensions between the countries.
Recently China accused the US authorities of harassing Chinese students on arrival at Washington's Dulles airport, subjecting them to lengthy questioning and trying to turn them into spies.
According to China's education ministry, more than 8 million students have studied abroad in the period between 1978 and the end of 2021, with the US, Britain and Singapore as the most popular destinations.