Coronation Street stars involved in the Channel 4 Twitter ‘sting’ have been sent warnings from soap bosses over their promoting products on social media

Producer Stuart Blackburn reportedly sent cast members letters ‘reminding them of their responsibilities’ after several of them were found to be promoting free products given to them by a bogus gifting room set up by Channel 4’s Dispatches.

Brooke Vincent, Catherine Tyldesley and Shobna Gulati were among those who were later pictured on their Twitter pages posing with bags they had been given as well as tweeting rave reviews of free health and beauty products.

It is not the first time that Corrie stars have taken to Twitter to promote their favourite products and services.

Antony Cotton ran into trouble with viewers after ‘promoting’ luxury shoe firm Grenson on his page, while Catherine Tyldesley apparently plugged a fitness company nine times in two days on her own page.

“The plugging of products is getting out of hand,” a source told The Sun.

“This is very embarrassing for the show and the people involved. Bosses want to make it plain the plugging of products and services on Twitter is against the rules.

Meanwhile EastEnders star Shona McGarty has also reportedly run into trouble after plugging two products on her own Twitter page.

The actress, who plays Whitney Dean in the soap, is said to have been ‘read the riot act’ by show bosses after promoting both a vocal boot camp and a Spanish language smartphone app.