Italy's top influencer Chiara Ferragni has apologised for misleading consumers over purchases of a Christmas cake.
Ms Ferragni, who has almost 30 million followers on Instagram, was fined €1.075m (£927,000) for claiming sales of a "designer" pink pandoro would help fund a children's hospital in Turin.
The cake's producer had given money to the hospital months before launching it, the competition watchdog found.
Ms Ferragni, 36, has promised to donate €1m to the Regina Margherita hospital.
In a statement posted to her followers, she said she had made a "mistake in good faith... to link a commercial activity with a charitable one".
Appearing on the verge of tears, she said she would appeal against the AGCM antitrust authority's ruling and "disproportionate and unjust" fine.
The "Pandoro Pink Christmas", which was labelled as being designed by Ms Ferragni, was sold last year for more than €9, well over twice the price of the classic unbranded pandoro produced by the Balocco company.
The watchdog found last Friday that buyers of the Ferragni-branded pandoro cake had been fooled into thinking that their purchases would contribute to the purchase of medical equipment for the hospital for the treatment of children with Osteosarcoma and Ewing's Sarcoma.
Anger surrounding the case prompted Prime Minister Georgia Meloni to speak out at the weekend against influencers who promoted "expensive cakes that make people believe they are charitable," although she did not mention Ms Ferragni by name.
One commentator said now that the "do-gooder" pandoro with pink icing sugar had been exposed as junk, Italians were wondering where that left "the princess of influencers as well as queen of social media".
Consumer group Codacons said it would launch legal action seeking compensation for anyone who had bought the cake thinking they were giving money to the Turin children's hospital. It said it was filing complaints with 104 Italian prosecutors alleging aggravated fraud.
The AGCM watchdog said false advertising had exploited consumers' "sensitivity to charitable initiatives, especially those aiding children with serious illnesses". This violated Italy's consumer code and constituted unfair commercial practice, it added.
It fined the manufacturer of the cake, Balocco, €420,000, and slapped a fine of more than €1m on two companies that manage Chiara Ferragni's trademarks and rights.
It said Balocco had already made a donation of €50,000 to the hospital months before the cake was put on sale, while the company had paid Ms Ferragni's two companies around €1m for the promotion.
