Amazon was slapped with a $35 million fine Tuesday after regulators in France determined that the e-commerce giant has an “excessively intrusive system” for keeping tabs on its warehouse workers.

The French Data Protection Authority, or CNIL, called out the company’s branch in the country, Amazon France Logistique, for requiring employees to use a barcode scanner to track their progress on tasks – such as storing items on shelves or packing them up for shipment.

Regulators said Amazon France Logistique set up three productivity tracking alerts that were found to be illegal – one that sent an error message if employees had scanned items “too quickly,” one that tracked “idle time” of 10 minutes or more” and one that tracked “periods of scanner interruption between one and ten minutes.”

“Indicators tracking the inactivity time of employees’ scanners were put in place,” the agency said in a statement. “The CNIL ruled that it was illegal to set up a system measuring work interruptions with such accuracy, potentially requiring employees to justify every break or interruption.”

The CNIL also accused Amazon of “excessive” storage of employees’ performance data regarding their daily asks.

The company was found to have committed several breaches of the European Union’s General Data Protection Regulation, or GDPR.

The agency said it investigated Amazon’s practices in France following a series of “press articles,” as well as complaints from Amazon warehouse workers.

“Such systems kept employees under close surveillance for all tasks carried out with scanners and thus put them under continuous pressure,” the agency added.

Amazon disputed the agency’s findings in a statement.

“We strongly disagree with the CNIL’s conclusions which are factually incorrect and we reserve the right to file an appeal,” Amazon said in the statement.

“Warehouse management systems are industry standard and are necessary for ensuring the safety, quality, and efficiency of operations and to track the storage of inventory and processing of packages on time and in line with customer expectations,” the statement added.

The scrutiny in France marks another headache for Amazon, which has faced allegations in the US of leaving workers with no choice but to pee in bottles due to strict productivity goals.

The company has denied wrongdoing.