Reports on Tuesday suggested the Portuguese, along with Italian businessman Alessandro Proto, was set to support the building of paediatric facilities across South America, per EFE (h/t Adriana Garcia of ESPN FC).
However, per The Portugal News, management agency Gestifute said the reports were untrue on Wednesday and "denied any links to the New York-based Brafman & Associates Law Firm, which announced the news on Monday."
Ronaldo, who recently won his fifth Ballon d'Or, is renowned for the work he does with various charities.
The forward is an ambassador for organisations like Save the Children, Unicef and World Vision. He is also a regular blood donor.
Earlier in the year, the Ballon d'Or trophy Ronaldo won in 2013 was auctioned off to raise money for the Make-A-Wish foundation; the silverware was eventually sold for £600,000.