The fine was imposed for “consciously refusing to report all the required information” concerning the purchase last year, Britain’s competition watchdog said.
Britain's competition watchdog has fined social network giant Facebook £50.5 million ($69.5 million) for a "deliberate" failure to supply information linked to its takeover of animated graphics startup Giphy.
The Competition and Markets Authority said on Wednesday the fine was imposed for "consciously refusing to report all the required information" concerning the purchase last year.
"We warned Facebook that its refusal to provide us with important information was a breach of the order but, even after losing its appeal in two separate courts, Facebook continued to disregard its legal obligations," Joel Bamford, senior director of mergers at the CMA, said in a statement.
"This should serve as a warning to any company that thinks it is above the law."
The CMA said it was the first time a company had been found to have consciously breached such an order.
"Given the multiple warnings it gave Facebook, the CMA considers that Facebook's failure to comply was deliberate."
Facebook hit out at the fine in a statement.
"We strongly disagree with the CMA's unfair decision to punish Facebook for a best effort compliance approach, which the CMA itself ultimately approved.
"We will review the CMA's decision and consider our options," it added.
It comes as Facebook faces a storm of criticism since a whistleblower leaked internal studies showing the company knew its sites could be harmful to young people's mental health.
US authorities have struggled to regulate social media platforms like Facebook amid criticism that the tech giants trample on privacy and provide a megaphone for dangerous misinformation.
US authorities on Tuesday said Facebook had agreed to pay up to $14 million to settle a government lawsuit accusing the tech giant of favouring immigrant applicants for thousands of high-paying jobs.
In the UK, the CMA on Wednesday added it had fined Facebook £500,000 ($689,000) for changing its chief compliance officer on two separate occasions without first seeking consent.
The watchdog also said its investigation into Facebook's takeover of Giphy remains ongoing.
Facebook announced in May 2020 its purchase of Giphy for a reported $400 million.
Giphy is a platform and search engine for "stickers" and other products using the graphics interchange format or GIFs.