Toy manufacturer Mattel has said it “deeply regrets” a misprint on packaging for dolls inspired by the new Wicked movie which listed the address for an adult website.

The company recently released the singing dolls ahead of the long-awaited film starring Cynthia Erivo and Ariana Grande.

But eagle-eyed fans posted images on social media showing the packaging had a pornography website on it, instead of the movie’s web address.

In a statement, Mattel apologised for the “unfortunate error” and advised parents that the misprinted website “is not appropriate for children”.

The BBC has seen online instructions on Mattel’s website, for both the Glinda and Elphaba dolls, listing the erroneous website underneath the Universal Pictures logo – the film studio behind the movie.

Mattel recommends the dolls for children aged four and above.

Fans who bought the doll posted about their surprise on social media.

“I purchased the Singing Elphaba doll and upon inspection, the website printed on the back side [of the] Mattel box, right above the barcode is listed as… an unaffiliated adult [not safe for work] 18+ website,” one person posted on Reddit.

“Anyone else seeing this!?”

In another post, a US-based woman said: “Went to Target and Walmart today and yeah, the Wicked dolls have the [porn] website listed.”

Mattel said the dolls had primarily been sold in the US.

It added: “We deeply regret this unfortunate error and are taking immediate action to remedy this.”

“Consumers who already have the product are advised to discard the product packaging or obscure the link and may contact Mattel customer service for further information.”

The Wicked movie comes after two decades of the musical on stage.

Set in the Land of Oz before Dorothy Gales’ arrival from Kansas, the movie covers the musical’s first act.

British actress Erivo plays Elphaba, a young woman misunderstood because of her green skin and who is yet to discover her power which will eventually lead her to becoming the Wicked Witch of the West.

She strikes up an unlikely friendship with classmate Glinda, played by Grammy-winning singer Grande, who will go on to become the Good Witch of the North.

The movie is set to be released in the US and UK on 22 November.