Cleaners from the Philippines and Indonesia were forced to work up to 17 hours a day and share beds with strangers while cleaning the four branches of the luxury gym chain Saints & Stars in Amsterdam, the Parool reported this week.

The workers were made to surrender their passports while the company organised their visas and work permits, the paper said. Many were recruited directly in their home countries.

The labour inspectorate confirmed that 23 undocumented workers were found during recent inspections at a gym chain in Amsterdam, without naming the company, the Parool said.

Saints & Stars is owned by Tom Moos, 31, son of millionaire René Moos, the co-founder and current chief executive of Basic-Fit, which operates 1,400 gyms across Europe.

On Wednesday evening, the inspectorate’s investigations unit arrested the bookkeeper of Saints & Stars on suspicion of forgery.

The Parool said it spoke to workers and reviewed WhatsApp conversations, photos, videos, audio recordings and emails exchanged with the labour inspectorate.

Several cleaners said they had to share a bed with strangers and were not allowed any personal space.

Tom Moos did not respond directly to questions from the paper, but the company issued a written statement.

“It pains us and saddens us that our conduct is now being questioned,” it said. “A key part of our company culture is to always support our people and help them where needed. Naturally, we are fully cooperating with the investigation.”

Meanwhile, several “influencers” and trainers who work with the gym have cancelled their agreements, the paper said on Friday.