European Union antitrust regulators are already probing Facebook Inc.’s two-month-old Libra digital currency project, according to a document seen by Bloomberg.

The European Commission is “currently investigating potential anti-competitive behavior” related to the Libra Association amid concerns the proposed payment system would unfairly shut out rivals, the EU authority said in a questionnaire sent out earlier this month.

Officials said they’re concerned about how Libra may create “possible competition restrictions” on the information that will be exchanged and the use of consumer data, according to the document, which is a standard part of an early-stage EU inquiry to gather information....