HS2 bosses have been criticised for sending thousands of worrying and misleading letters.
Recipients were advised their properties would be at risk of demolition in order to make way for the new high-speed rail network. In reality, residents of properties that would be affected had already been informed at an earlier date.
The error has further fuelled anger with the controversial development and is the latest in a line of communication blunders by transport officials.
David Lidington, the MP for Aylesbury, said: "It is unforgivable that HS2 Ltd's wretched mishandling of its communications should twice now have caused people unnecessary fears."
Previously, a drafting error caused residents to be informed that access would be required to their properties for 203 weeks, instead of the intended time frame of two to three weeks.
Meanwhile, USB sticks containing information on the environmental impact of the network were issued with 877 pages missing. The lost data concerned 17 constituencies along the length of the route.