Manafort in recent weeks has either consulted or worked with a Chinese construction billionaire looking to expand his business overseas and a telecommunications firm interested in regulatory approval from governments in Asia and the Middle East, as well as an investment fund claiming links to the Chinese government, according to documents and interviews.

Manafort quietly consulted on a proposal under which the Chinese fund -- the China Development Fund -- would invest $30 billion or more in the Puerto Rican government's bond debt and possibly the island's critical infrastructure, according to documents and interviews with four people familiar with the negotiations, including a Manafort business partner.

One of the people, a lawyer involved in the discussions, said Manafort indicated that he could convince the Trump administration to support any resulting deal, because he's remained in contact with Trump's team, and that he played a role in helping to soften Trump's tough campaign rhetoric on China.