The patient had endured years of severe pain and debilitating health complications due to the tumour
Jun Wei Yeo, also known as Dickson Yeo, entered his plea in federal court in Washington to one charge of operating illegally as a foreign agent.
In the plea, Yeo admitted to working between 2015 and 2019 for Chinese intelligence "to spot and assess Americans with access to valuable non-public information, including US military and government employees with high-level security clearances."
It said Yeo paid some of those individuals to write reports that were ostensibly for his clients in Asia, but sent instead to the Chinese government.
The guilty plea was announced days after the US ordered China to close its consulate in Houston, labelling it a hub of spying and operations to steal US technology and intellectual property.
The US has also arrested four Chinese academics in recent weeks, charging them with lying on visa applications about their ties to the People's Liberation Army.
In a "statement of facts" submitted to the court and signed by Yeo, he admitted he was fully aware he was working for Chinese intelligence, meeting agents dozens of times and being given special treatment when he traveled to China.
The plea announcement came five weeks after an indictment of Yeo was unsealed, cryptically accusing him of acting illegally as an agent of an unspecified foreign government.
He had been arrested after flying to the United States in November 2019.
Yeo was recruited by Chinese intelligence while working as an academic at the National University of Singapore.
He had researched and wrote about China's "Belt and Road" initiative to expand its global commercial networks.
According to his LinkedIn page, he worked as a political risk analyst focused on China and ASEAN countries, saying he was "bridging North America with Beijing, Tokyo and Southeast Asia."
In the United States, the court filing said, Yeo was directed by Chinese intelligence to open up a fake consultancy and offer jobs.
He received more than 400 resumes, 90 percent of which were from US military or government personnel with security clearances.
Yeo gave his Chinese handlers the resumes that he thought they would find interesting, according to the court documents.
He said he had recruited a number of people to work with him, targetting those who admitted to financial difficulties.
They included a civilian working on the Air Force's F-35B stealth fighter-bomber project, a Pentagon army officer with Afghanistan experience, and a State Department official, all of whom were paid as much as $2,000 for writing reports for Yeo.
Yeo was "using career networking sites and a false consulting firm to lure Americans who might be of interest to the Chinese government," said Assistant Attorney General John Demers in a statement.
"This is yet another example of the Chinese government's exploitation of the openness of American society," he said.
The patient had endured years of severe pain and debilitating health complications due to the tumour
The concert is set to take place on April 27
Move aims to amplify Zambia’s renewable energy capacity
More vertiports will be set up in strategic locations across Abu Dhabi, including major business hubs and tourism destinations
Kerala will decide the fate of 194 candidates as polling on all 20 parliamentary constituencies will be held in the second phase
Pecker is a key witness in the case against the former US president, who is accused of falsifying business records to cover up hush-money payment
The oil and gas conglomerate and Fifa, the world governing body, sign major sponsorship agreement
Toomaj Salehi risks being hanged after the conviction on the Shariah charge of "corruption on Earth" by a Revolutionary Court