Camelot’s breaches included failings in direct debit instruction, security measures, Post Office controls and publishing incomplete results for its Olympic medal prize promotion.

However, Camelot’s most notable offence was incorrect prize outcomes on its mobile app, meaning players may have seen a “non-winning” message even if they possessed a winning ticket.

Camelot said: “While we have always sought to run The National Lottery to the highest possible standards, we accept that, at the time of these incidents, our standards in certain areas weren’t as rigorous as they should have been and for that we’re sorry.”

Despite the fine, the Gambling Commission initially put its investigation on hold while Camelot created an operational excellence programme.

Camelot has also been acknowledged for engaging positively with the regulator and “early acceptance of failings.”

Richard Watson, Gambling Commission Executive Director, said: "Camelot has taken a number of steps to rectify the issues and given us assurances that they now have the right processes in place to prevent reoccurrences.

"It is crucial that the National Lottery is run fairly, safely and with integrity and we'll continue to hold Camelot to account."