Northeye was purchased to increase capacity in the asylum system when the previous government was spending £8m a day on hotel accommodation and dealing with an increase in asylum applications.
It was originally intended as non-detained accommodation for up to 1,400 men who had arrived in the UK on small boats, meaning residents would be free to come and go.
But in May 2023, the government concluded the site was unsuitable for that purpose and said it would be used instead for detained accommodation.
To date, no work has been carried out to make it habitable.
Dr Kieran Mullen, Conservative MP for Bexhill and Battle, said it was “not fair” on the residents in his constituency to go through this.
“I absolutely regret that we didn’t acquire this site in the best possible way, and I’m really glad that the Home Office has learnt a lesson from this,” he said.
Labour said the report raised "serious questions" about opposition leader Kemi Badenoch's judgment in appointing Mr Jenrick as shadow justice secretary.
"The Tories spent 14 years wasting taxpayers' cash to leave Britain with a £22bn black hole. Now the National Audit Office has revealed the extent of the Conservatives' reckless spending," a party spokesman said.
"It's the same old Tories, they haven't learned anything. Labour is fixing the foundations to deliver change, and clean up the mess the Tories left."