Money will fund the construction of a 550km railway between Dar es Salaam and Matukupora.
The property will be auctioned to settle a Sh1.2bn loan.
Watchdog asks developer to redesign the project or seek an alternative site.
298,889 citizens had registered on the Boma Yangu online portal as of June 29, 2020.
The project is set for completion in July 2024.
Most prospective buyers have not been remitting any monthly contributions.
The Sh1.9 billion 'village' project was launched in March 2014.
Controversial rent control ideas are emerging across major cities.
HFDI will quit construction business later this year after completing ongoing projects.
These facilities allow businesses the opportunity to operate inexpensively in a prime address.