A mysterious shell company formed just weeks before the Republican National Convention dropped $3.1 million to purchase 11 luxury condos in a Las Vegas tower co-owned by Donald Trump in the months leading up to his election, USA Today reported Friday.

No one will acknowledge who is behind the company, known only as Milan Investment Limited.

The address associated with the company tracks back to the strip mall office of a financial services firm, whose owner told USA Today he was “completely in the dark” about what Milan Investment was or why the company would use his address. The newspaper’s effort to track down the listed officers for Milan Investment, Jun Xu and Qi Huang, were similarly fruitless. Reporters came up empty-handed after contacting every phone number and address found for the pair in both the United States and Canada, where they’re also listed as owners of multi-million condos.

This kind of murky real estate purchase is just one of the many practices that ethics experts worry wealthy people, companies and foreign interests may take advantage of in order to curry favor with the President. Trump has placed his assets in a trust run by his adult sons, who continue to manage his real estate business, and from which he can withdraw money at any time without disclosing it to the public.

Walter Shaub Jr., director of the Office of Government Ethics, called the arrangement “wholly inadequate,” saying the United States “can’t risk the perception that government leaders would use their official positions for professional profit.”

USA Today’s exhaustive investigation found that Trump’s companies stand to earn up to $250 million in property sales in the United States alone, and that shell companies like Milan Investment are able to snatch up huge quantities of that available real estate, leaving the public in the dark.

Read the full report at USA Today.