Costumes on the Party Pieces website include ‘Midnight Mischief’ – a sexy-witch design with a corset and mini skirt – for girls aged four to six. Picture: Website screenshot

London - A company owned by the Duchess of Cambridge’s parents has come under fire for selling sexualised Halloween outfits for children as young as four.

Costumes on the Party Pieces website include ‘Midnight Mischief’ – a sexy-witch design with a corset and mini skirt – for girls aged four to six.

A survey of parents found 98 percent would not let their daughters wear the outfit, which is sold by the firm run by Carole and Michael Middleton.

Another costume on the site is a Headless Horseman with a bloodied stump for a neck, aimed at children as young as eight. The two outfits are among a "nasty nine" list of fancy dress costumes identified by the website ChannelMum.com.

The site found that two thirds of parents believe Halloween costumes are "too frightening" for very young children.

Disgusted parents were particularly critical of a Burnt Zombie Child outfit, which they said was insensitive in the wake of the Grenfell Tower tragedy.

The £34.99 (about R600) costume, sold by Escapade, is aimed at eight to ten year olds. Party Pieces did not respond to a request for a comment.