An almost 20-year-old case of a Beijing student left paralysed after allegedly being poisoned was back in the spotlight in Chinese state media Monday after a petition was posted on the White House website.

Zhu Ling suffered severe brain damage after, according to the petitioners, she was poisoned with thallium by her roommate Sun Wei when the two were studying chemistry at Tsinghua University in 1994.

Thallium, a soft metal, has long been used as a murder weapon as it dissolves in water and is odourless and tasteless.

Sun, who now lives in the US, "had the motive and access to the deadly chemical", said the petition, which calls for her deportation back to China.

By Monday afternoon it had attracted more than 100,000 signatures -- meaning that the Obama administration will issue a response, according to the White House website.

"The number of signatures is growing rapidly, with an average of 100 people signing every minute," the state-run Global Times newspaper said earlier.

The case is the subject of intense speculation on China's hugely popular Internet chat rooms, with many claiming that a previous investigation by Chinese police was dropped because of Sun's family connections.

Sun has never been formally charged. The state news agency Xinhua quoted her as saying in an online posting last month that she wants to see those responsible brought to justice.

Her grandfather Sun Yueqi was a senior official of Chiang Kai-Shek's Kuomintang before allying with the Communists in 1949, just before they took power.

He is said to have been close to the father of former Chinese leader Jiang Zemin.

Another relative, Sun Fuling, was vice chairman of the advisory Chinese People's Political Consultative Conference when Zhu was allegedly poisoned, having previously been vice mayor of Beijing.

"The White House website is now the PRC's (China's) State Bureau for letters and calls," said Luo Changping, deputy managing editor of state-run business magazine Caijing.

The US-based Help Zhu Ling Foundation, which collects donations for the Zhu family, issued a statement on its own weibo page Sunday distancing itself from the petition, saying it contained factual errors and was "hasty".

A commentary by Xinhua on Monday called for the facts of the case to be established. "Only with the emergence of the truth will there be trust in the judicial system," it said.