A number of top brands have reportedly raised concerns about their adverts on Mumsnet after their marketing appeared next to "offensive" swear words posted by users.

Confused.com, National Trust and Italian fashion brand Bulgari are among the companies concerned by profanity on the popular internet forum, which is visited by millions of parents every month, according to the Times.

Banner ads for major firms have appeared on posts called "Is this w**ky?" and "I can't f**king do this anymore", which generated hundreds of comments.

One frustrated user in the latter post described their son's tantrums by saying: "He’s proceeded to just yell at me all f***ing morning. I am f***ing broken."

A National Trust spokesperson told the Times they had requested that their adverts were removed from posts containing swear words, while a representative from price comparison website Confused.com said they would take measures to prevent their ads appearing "on any page that is deemed offensive in any way".

The companies pay for advertising space on Mumsnet and a number of other sites through agencies who use software to target their specific consumers.

Parents vent their frustrations about issues ranging from potty training to internet safety on Mumsnet, who have said they are not "over prudish" about swearing.

The site, which makes money through advertising, sponsors and events, generated a turnover of £7.2million last year and has become one of the most influential internet forums in the UK since it was founded by Carrie Longton and Justine Roberts in 2000.

Ms Roberts said: "We haven't been contacted by any advertisers with any concerns about swearing on Mumsnet and we have no plans to change our policy on allowing swearing on our forums. Mumsnet is after all a site for grown ups which people visit to get advice, support and sometimes to let off a bit of steam."

The news that top brands were reportedly concerned about their ads due to swearing drew mixed reactions from Mumsnet users.

"F**k me, [Mumsnet HQ], is this true?" asked Paffle.

"Are people that bothered by swearing? Please tell me you're not going to ban swearing."

Impostersyndrome said: "I'm with the advertisers, I'm afraid. For a site that's meant to be full of women more intelligent than average, I'm astonished at how sweary it is. In no way does it reflect my reality at home or at work."

Other advertisers on the site include Marks & Spencer, TK Maxx and Asda.