Nuneaton and Bedworth Borough Council apologises over the matter.
The Commons' Defence Committee says in a report that the MoD used secrecy as a "shield" against proper expertise.
It is believed to be the first time that MI5 has been directed to pay compensation to a journalist.
John Adams' personal data was leaked when his healthcare provider was hacked.
The record fine comes after around 37.5 million users had their private data exposed.
Horizon Academy Trust says an investigation is under way to establish how the data breach happened.
The force apologises for the incident and says changes have been made to stop it happening again.
Almost £40 million pounds has been paid out to more than 5000 police officers and civilian staff impacted by a 2023 data breach.
The government said medical data of 500,000 people was affected but no personally identifiable information had been made available.
