Ren Xiaoping, who along with Italian surgeon Sergio Canavero, hope to attempt the procedure within two years, but only if the preparatory research and tests go according to plan, Ren said.

“A lot of media have been saying we will definitely attempt the surgery by 2017, but that's only if every step before that proceeds smoothly,” Ren told AFP.

Canavero, who leads the Turin Advanced Neuromodulation Group, first announced his project in 2013, saying at the time that such a procedure could be possible as soon as 2016.

But this timeline seems extremely unlikely given the numerous obstacles and gaps in knowledge

The man who has volunteered for the operation is Russian-born Valery Spiridonov, 30, who suffers from Werdnig-Hoffmann disease, which is a progressive and incurable wasting ailment.

Ren said the operation would likely take place at Harbin Medical University in China's northeast Heilongjiang province.

He declined to say where a donated body might come from and said he was unsure if the donor would be Chinese.

High demand for organs in China and a chronic shortage of donations mean that death row inmates have been a key source for years, generating heated controversy.

China has pledged not to use the organs of executed prisoners, but experts have voiced scepticism about the plan, arguing that organs will continue to be harvested from inmates but that they will now be classified as “donations”.

China banned trading in human organs in 2007, but demand for transplants far exceeds supply in the country of 1.37 billion people, opening the door to forced donations and illegal sales.

Organ donations are not widespread as many Chinese believe they will be reincarnated after death and therefore feel the need to keep a complete body.