The ruffled robe-like outfit Beyonce wore in her first photoshoot with her newborn twins was selected from a Spanish menswear line.

The Formation hitmaker surprised her Instagram followers in the early hours of Friday (14Jul17) by sharing the first picture of her baby son and daughter, confirming their unique names as Sir Carter and Rumi as she celebrated their one-month birthdays.

Beyonce went topless for the image, wearing a billowing floral purple jacket over turquoise panties with a matching veil as she cradled the twins across her chest. The snap was taken in front of a large flower display, reportedly in the garden of her and husband JAY-Z's Malibu, California rental pad, which overlooks the Pacific Ocean.

Now it's been revealed the clothing Beyonce chose to introduce fans to her new babies was actually plucked from 'romantic' menswear label Palomo Spain, and was originally debuted by male model Jason Harderwijk as part of the brand's spring/summer 2017 collection.

Designer Alejandro Gomez Palomo reveals he had been contacted by Beyonce's stylists for a sample last autumn (16), and the singer subsequently ordered a custom version of the silk organza piece and had it tailored into a gown.

However, he never thought Beyonce would get to use the outfit after announcing her pregnancy in February (17).

Palomo tells Vogue.com, "(I thought), 'OK, she won't wear it, oh well.'"

So he was just as stunned as the superstar's fans when he set sight on Beyonce's first picture with the twins, which has already racked up over eight million 'likes' in less than 24 hours.

"This is a really big surprise, obviously," he smiles. "I love the picture. It's just really beautiful. It's special."

Rumi and Sir Carter are siblings for Beyonce and JAY-Z's five-year-old daughter Blue Ivy.