In April this year, the Bank was given extra tools to control the residential mortgage market.
Those powers could now be extended to limit borrowing by landlords who buy property to rent out.
Earlier this week, the governor of the Bank of England, Mark Carney, expressed concern about buy-to-let.
He said he was worried that if house prices began to fall, investors might sell in large numbers, which could destabilise the economy.
Now the Treasury has suggested that the Bank could order banks and building societies to limit the sums they lend to landlords.