A former cashier at the Fondation Beyeler in Basel, Switzerland, has been convicted of embezzling almost CHF 900,000 ($1 million).

An internal investigation showed that the unnamed 54-year old woman employed various tricks over 11 years to divert money from ticket sales. In one common ruse, she would sell the same ticket twice by telling visitors that their ticket could not be printed due to a technical problem and giving them the receipt instead. She would then resell the ticket to a second customer. She arose the suspicion of her colleagues in 2019 when they noticed that she had been canceling their ticket sales for no apparent reason.

The woman would also issue emergency preprinted tickets intended for use during busy periods without registering them in the system or use her colleagues’ cash register codes to cancel their sales and pocket the money. Two of these employees testified against the woman in court.

She has been sentenced to three years and seven months in prison and must pay the museum back the full sum that she stole plus interest and a fine of several thousand dollars, according to Schweizer Radio und Fernsehen.

Prosecutors later found that the woman started the thefts within the first year of joining the museum in 2008. She became a manager in 2010 until she was fired in 2019. Large sums of cash had been deposited in her bank account and significant amounts spent on luxury items, like clothes, travel, and cars.

The Fondation Beyeler is one of Switzerland’s most visited art museums. It is currently staging an exhibition of works by Jean-Michel Basquiat.