Britain's Duchess of Cambridge gets sent marshmallows by her brother.

Britain's Duchess of Cambridge

Britain's Duchess of Cambridge

James Middleton, who co-founded the marshmallow printing company Boomf, has quipped that he sends his sister Kate and the royals the unique gifts.

When asked if he's ever given any of his edible treats to the royal family, he shared: "That is a state secret. To be honest, they've heard me talk about them so much, that I need to give them something different now."

The 28-year-old entrepreneur also revealed the business is "growing fast" and says he regularly borrows things from his parents, Carole and Michael Middleton's business as they're based just next door.

He said: "I've been working startup hours, evening and weekends since we started. We've quadrupled our turnover this year."

"Growing that fast takes a huge amount of effort. Our factory is next door to my parents' business, so occasionally we pop over to borrow sellotape - but apart from that it's totally independent."

And James' company have started recruiting bright young minds for internships.

He told the Daily Express newspaper: "Boomf is all about communicating via marshmallows. There are no established experts in that field, so we are keen to reach out and find new talent who bring fresh perspectives.

"So many of our best team members have joined us straight out of school or university."