Kate Middleton with Fabian Bate.
Kate Middleton met with 9-year-old Fabian Bate in September and sent him a letter earlier this month. REUTERS

As the Duchess of Cambridge prepares to announce the charitable causes and organizations she will support, she has been advised to shun the U.N.-affiliated Blue Heart Campaign.

The campaign works to raise awareness about human trafficking and its impact on society. But the issue is thought to be too political for someone close to the head of state - the Queen.

The Daily Mail reported that the Duchess was keen to work with the organization and is close friends with Lady Natasha Rufus Issacs and Lavinia Brennan, whose fashion label Beulah has close links with Blue Heart. Issacs is also an old pal of Prince William's and attended the royal wedding in April.

As per recent reports, the Duke and the Duchess have been visiting several organizations to select the causes to support. They are particularly aiming for charities that work for terminally ill patients and for children afflicted with cancer and other serious illnesses.