US lawmakers are probing Credit Suisse Group AG’s compliance with sanctions related to Russia’s invasion of Ukraine and have asked the Swiss bank to provide all relevant documentation.

Credit Suisse has been asked to hand over documents related to the financing of yachts and private jets owned by potentially sanctioned individuals, according to a letter sent by the Committee on Oversight and Reform of the House of Representative to the bank’s Chief Executive Officer Thomas Gottstein on Monday.

The probe comes after recent reports said Credit Suisse had instructed hedge funds and investors to destroy and erase information related to its dealings with clients.

Credit Suisse did not immediately respond to a Reuters request for comment.

The letter, sent by Chairwoman Carolyn Maloney and Stephen Lynch, the chairman of the Subcommittee on National Security, expressed concern over the timing of the bank’s instruction to destroy documents as it coincided with Switzerland’s statement that it would join other countries in imposing sanctions.

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Credit Suisse has been asked to comply by April 11 and will need to send documents starting from January 2017 to present day, according to the letter.