The UK and China have held "preliminary discussions" regarding giving Beijing's state-owned railway firm a role in the construction of the new HS2 high-speed rail line.
Department for Transport (DfT) officials confirmed that “preliminary discussions” had taken place but said no “concrete commitments” had been made.
“The DfT is always keen to learn from the experience of others and to consider approaches that offer value for money to the taxpayer,” one official said.
China's state railway company told the UK that it could build the line in just five years for much lower cost, according to a letter seen by Building magazine.
The talks follow the announcement by Boris Johnson this week approving the controversial HS2 project, despite an official review saying that the costs could exceed £100bn, against a budget of just £62bn.
Under current plans, the line will not be fully completed until 2040 while Mr Johnson has said he wishes to see it brought forward to 2035.
Allowing Beijing a further role in UK infrastructure project may bring further controversy on the Johnson government, who has previously been the recipient of anger by US President Donald Trump, and many Tory MPs, over his decision to allow Chinese tech giant Huawei to supply equipment for the new 5G mobile network.
While China has historically been capable of building mass high-speed railway links, British officials are said to be sceptical that it would be possible given the two distinct systems with the UK prioritising property rights, protected landscapes and powerful lobbying groups.