Prince Harry and his fiancee Megham Markle. (Xinhua Agency)

A fashion brand has renamed one of their coats The Meghan after she wore it to her and Prince Harry's photocall just hours after their engagement news was announced.

Line the Label founder John Muscat has named the white wrap coat after the former 'Suits' star after she donned it for the occasion, but he didn't find out she was sporting it until the pictures started appearing on news websites worldwide.

Meghan Markle's white wrap coat has been named The Meghan. (Xinhua)

He said: "I found out when you found out - and I was having a slow morning so I was a little bit surprised as I popped out of bed.

"I was met with a lot of text messages that kept building and building.

"I'm very honoured and surprised. Obviously, I knew that I'd given her the coat but I had no expectation that she would be wearing it for that particular engagement."

John previously gifted her the wrap coat in white, burgundy, black and blush, because he thought it matched her style perfectly. 

He added: "Meghan has a style to her that's very simple, very chic, and I think the wrap coat fits into that. 

"It's something that has been in our collection for a number of years. It's just casual and sophisticated."

The brand's website crashed as fans flocked to try to buy the coat, even though it wasn't on sale online, and John admitted it may be back in stock in March. 

He added to HELLO! magazine: "The winter white is something we're trying to get back into stores by early March."

Meghan, 36, and Harry, 33, posed for pictures at the White Garden - a memorial spot for the royal's late mother Princess Diana - in the grounds of Kensington Palace just hours after his father Prince Charles had announced their engagement. 

The couple will tie the knot at Windsor Castle in May.