Robbie Williams posted a photo of himself on Twitter in the throes of food poisoning.
Williams, 37, became violently ill on Friday after eating, according to the Sun, "grilled Danish black lobster with lobster salad and saffron aioli".
Take That had been due to play the second of two dates in Copenhagen's Parken stadium on Saturday night (July 16) but had to pull out at the last minute.
Williams, who has spent the past 72 hours running to the bathroom, posted a photo of himself on Twitter showing himself on a drip and looking very much worse for wear. He also thanked fans for their support.
"Hey folks, thank you for your messages and love," he wrote on his blog. "I'm not completely out of the woods yet but feeling much better. Gutted for everyone involved with the tour, feeling dreadful for letting the fans down. I'm so, so sorry. Here's me and my drip."
Williams has ended up with dehydration and in need of the drip because he has lost so much fluid.
In a statement, the band said they were "devastated" to have cancelled a gig for the first time ever, adding it was "a horrible decision to make and one we agonised over".
The Sun quoted a source saying: "It hasn't been pretty. It's all down to a dodgy lobster he ate at a hotel.
"Jason and Mark wanted to go ahead and do it without him, so as not to let down the fans.
"But there was something to do with the insurance that stopped them.
"I think they would have had to pay back on the tickets if people there said they wanted to see Robbie and they'd done the gig without him.
"They are in Amsterdam tomorrow and I think everyone is just hoping he'll be well enough to perform then."