Prince Charles received a £1 million (NZ$1.96 million) donation for his charity from relatives of Osama bin Laden, according to a report.
The United Kingdom's The Sunday Times said The Prince of Wales' Charitable Fund (PWCF) received the donation in 2013 from brothers Bakr and Shafiq bin Laden, half-brothers of Osama bin Laden.
The future king is said to have held a private meeting with Bakr at Clarence House in London on October 30, 2013, two years after Osama was shot dead by US special forces at a compound near Islamabad in Pakistan.
Clarence House confirmed the bin Laden brothers had given money to the royal charity but disputed reports that Prince Charles brokered the deal or made the decision to accept it.
"The Prince of Wales' Charitable Fund has assured us that thorough due diligence was undertaken in accepting this donation," a spokesperson said.
"The decision to accept was taken by the charity's Trustees alone and any attempt to characterise it otherwise is false."
Sir Ian Cheshire, chairman of the PWCF, also said due diligence was conducted and the decision to accept the donation was taken wholly by the trustees.
"The donation from Sheikh Bakr bin Laden in 2013 was carefully considered by PWCF Trustees at the time," he said.
"Any attempt to suggest otherwise is misleading and inaccurate."
But The Sunday Times alleged that Prince Charles agreed to accept the donation despite the objections of his advisors.
One of his household staff reportedly warned him there'd be national outrage if it became known his charity had accepted money from the family of the man who orchestrated the September 11, 2001 terrorist attacks.
"The fact that a member of the highest level of the British establishment was choosing to broker deals with a name and a family that not only rang alarm bells, but abject horror around the world … why would you do this? What good reason is there to do this?" a source told The Sunday Times.
"I just didn't feel any member of the British royal family should be involved in that sort of undertaking."
There's no suggestion that brothers Bakr and Shafiq have sponsored or been involved in acts of terrorism, the Sunday Times said.
It comes a month after it emerged Prince Charles accepted bags of cash totalling €3 million (NZ$4.95 million) during meetings with former Prime Minister of Qatar Sheikh Hamad bin Jassim bin Jaber al-Thani.
The cash was reportedly handed to him in a suitcase on one occasion and carrier bags on others.
It was donated into the accounts of the PWCF and there's no suggestion the payments were illegal.
