BERLIN (AP) — A German privacy watchdog says it has opened an investigation into clothing retailer H&M amid evidence that the Swedish retailer had committed “massive data protection breaches” by spying on its customer service representatives in Germany.

Hamburg’s data protection commissioner said in a statement Monday that a hard drive containing about 60 gigabytes of data revealed that superiors at the site in Nuremberg kept “detailed and systematic” records about employees’ health, from bladder weakness to cancer, and about their private lives, such as family disputes or holiday experiences.

Johannes Caspar said the records, which were accessible to all company managers, showed that employees were comprehensively spied on “in a way that’s unparalleled in recent years.”

H&M said in a statement that it takes the case “very seriously” and expressed its “honest regret” to the affected staff. The company said it was cooperating fully with data protection officials and had taken a number of measures in response to the incident.

The Hamburg data protection office said it would decide on possible fines for H&M in the coming weeks.