The advertising watchdog is investigating a poster promoting Scottish comedian Fern Brady’s latest tour following a complaint it “mocks the Christian faith”.

Promotional materials see the comic squirting breast milk onto a man dressed in religious ceremonial clothing.

On the poster she is standing by a stained-glass window which says “I gave you milk to drink”, which is the name of her latest comedy tour.

The Advertising Standards Authority (ASA) confirmed it has received a complaint about the paid-for online ad.

An Advertising Standards Authority (ASA) spokesperson said: “The complainant has challenged whether the ad is offensive because they believe it mocks the Christian faith.

“We have launched a formal investigation. But no decision has been reached on whether the ad breaks the UK advertising rules.”

The watchdog has said is will publish its findings in due course.

The comedian acknowledged the complaint in a post on social media, writing: “Whoever complained about the poster, thanks a lot.”

Brady rose to fame as a comic at competitions such as the Edinburgh Fringe Festival and has appeared on comedy panel shows such as 8 Out of 10 Cats and Taskmaster.

She has previously spoken about how receiving a late autism diagnosis in 2021 impacted her life.

Fern Brady has been contacted for comment.