Greek police have found about 1.1 million euros ($1.3 million) in cash hidden behind a false brick wall at the home of the owner of Pizza Fan, a nationwide pizza chain accused of evading 25 million euros in sales tax since 2022.
Twenty-two people have been arrested so far, police said.
Officers discovered the hiding place in a walk-in closet at the owner's villa in Athens' northern suburbs, reached through a concealed door.
Gold jewelry and luxury cars were seized earlier.
Investigators say the scheme was run through the company's call center, which the owner kept under his control even as he franchised the chain's roughly 100 outlets.
Operators asked customers whether they would pay in cash or by card. Cash orders were logged as free "treats," and customers received a delivery note instead of a receipt, allowing the sales to go unreported.
A developer allegedly built software that recorded the false data. In wiretaps, police heard a customer calling back to complain that his receipt had not arrived.
The first nine people arrested, including the owner, his deputy, the programmer and accountants, are suspected of forming the core of the operation.
Twelve more arrests followed during checks of 23 franchise stores in Athens and Thessaloniki, where about 100,000 euros was seized.
The organized crime investigation began about five months ago after a complaint by a former employee.
Greece has stepped up efforts against tax evasion in recent years, expanding electronic payments and digital receipts to close one of the European Union's largest gaps in sales tax collection.