The actress, who plays Sophie Webster in Coronation Street, can be seen in pictures puffing on what seems to be a spliff.
A source said: “She was smoking it in full view of anyone who wanted to watch. She seemed totally relaxed and not bothered at all about who could see her.
“She was so casual about it that if you didn’t know it was a joint, you would have thought she was just smoking a cigarette.”
Although smoking marijuana is completely legal in Amsterdam so Brooke was breaking no laws, in an interview a few months ago she claimed she never touches drugs.
She said at the time: “I’ve never taken them. They can put you in a situation that wrecks your life and those around you. I don’t get off my head, roll out of pubs or take drugs. I have a quick cig, that’s all.”
That wasn’t the first time that Brooke had spoken out about being against drugs. In 2012, her character in Corrie was involved in a car crash after taking drugs.
At the time, Brooke said: “I’ve never taken drugs, but I wanted to highlight the dangers they can cause.”
As she boarded her flight to Amsterdam last week, Brooke tweeted excitedly: “It’s about to go downnnnnnn…..”