Harry, Meghan split away from William, Kate's shared charity

Prince Harry and Meghan Markle will again separate themselves from Prince William and Kate to set up their own charity.

The Royal Foundation, a charity currently run for both pairs of royals as a vehicle for their humanitarian work, officially announced on Thursday (local time) that the Harry and Meghan would start their own foundation.

"The Duke and Duchess of Sussex will establish their own new charitable foundation with transitional operating support from The Royal Foundation," the foundation said in a statement.

The move had been signalled in May, but the final decision didn't come until Thursday when a review of the charity's structure was concluded.

The Royal Foundation drives programmes focussing on mental health, wildlife conservation, young people and the armed forces community. Harry and Meghan will continue to be involved in the foundation's mental health programme.

"These changes are designed to best complement the work and responsibilities of Their Royal Highnesses as they prepare for their future roles, and to better align their charitable activity with their new households."

But the split has again prompted questions about a rift between the couples, with some British outlets speculating if it was a continuation of their "feud".

Royal commentator Duncan Larcombe told Fabulous Digital it seemed "odd".

"Why separate when you are both backing the same causes? Whether this is a sign of a rift, this is certainly a sign of division."

Earlier this year there were reports of Kate telling Meghan some of her treatment of staffers was unacceptable. The couples have also split their households, while Harry and Meghan have started their own Instagram account.

"So basically Wills doesn’t want to be tainted by the Circus of Meghan & when the divorce happens it will be easier to merge Harry's charities with the original. Solid advice from Will's advisers I would say!" said one Twitter user.

Royal aides, however, shut down speculation on Thursday, saying they would still appear together at royal functions and engagements.

Others defended the split online, saying that the couple didn't need to be glued at the hip.

"Seriously look at the other royals like Prince Charles, Princess Anne, Prince Andrew and Prince Edward those people are not joined at the hip all the time or called the 'Fab 5' because they are doing their own thing," said one Twitter user.

"I don’t recall anybody saying those people were in a 'feud'."

Historian Marlene Koenig told Time magazine that it was uncommon for siblings in the royal family to share charities.