Leaked documents obtained by French daily Le Monde have revealed new details about the investigation into Swiss bank UBS amid accusations the bank was actively prospecting French clients to help them avoid tax.

According to the newspaper, the documents from the tax authority’s investigation include evidence that UBS AG was knowingly helping French citizens hide money from the taxman. The bank has denied the charges.

UBS is currently on trial in France for illegal solicitation and laundering the proceeds of tax fraud between 2004 and 2012. In 2014, judges estimated that the Swiss-headquartered bank had helped French taxpayers hide between 13 and 23 billion euros (about $14.5 to $25.6 billion).

According to one of the internal UBS documents published by Le Monde, bank employees were urged to follow strict protocols to preserve clients’ secrecy when traveling abroad. UBS workers were advised not to carry any client data, and to coordinate a “story” with travel companions in case they were questioned by customs.

“If you have sensitive data with you [on your UBS laptop], type three times a wrong PIN and access will be blocked,” employees were advised should authorities have demanded to inspect their computers.

It was revealed last month that 38,000 accounts had been opened for French clients in the Swiss bank. French authorities said that 4,206 tax evading clients – scared by the end of bank secrecy in Switzerland – had regularized their situation by September 2015. The majority of those clients were entrepreneurs, CEOs and business owners. Le Monde also mentions artists, athletes and doctors.

The French government has recouped at least 3 billion euros ($3.3 billion) in previously unpaid taxes through the voluntary disclosure program.

Head of UBS France Jean-Frédéric de Leusse told Le Monde the bank has been cooperating with authorities, and had measures in place to ensure clients weren’t using their account to evade taxes.

"Both in France and in Switzerland since mid-2012, all customers had to prove that they were in order in their tax returns or had entered a regularization process,” he explained. “Otherwise, their accounts are closed and a traceable bank check delivered.”

UBS had sought to settle with French authorities and avoid a trial, however it looks likely the bank will face courts in the coming months. A ruling against the bank could result in a multibillion-euro fine.

It’s not the first time UBS has been the subject of official government probes: American, German and Belgian authorities have investigated the bank for similar irregularities in the past.

In 2009, UBS agreed to pay a $780 million fine to the U.S. to settle a tax evasion case, and in early 2015 confirmed it was again under investigation by American authorities.

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