The Metropolitan Police has informed would-be officers who passed its recruitment stages successfully that their applications have been rescinded.
Approximately 2,000 candidates were left in limbo when the force announced a recruitment freeze in February.
Several applicants told the BBC they were shocked, but had been told the "economic climate" was to blame.
The Met Police admitted applicants had been notified but said: "We are still recruiting."
One of the candidates involved, who was wary of giving his name as he did not want to be penalised if he made any future applications, said: "I received a call earlier which just tore my dreams apart.
"The person on the phone said all of the applications were going to be rescinded and there would be no start dates for at least two years.
"When they do start to recruit again, none of our pass results are going to be taken into consideration and we have to start again from scratch."
"I began my application process at the start of last year and it was a bad enough blow when the recruitment freeze happened. But in April, we got another letter saying it was likely to be positive news.
"Now I'm so angry and disappointed. They should have told us earlier."
He said he wondered how the police were going to cope with training officers for the 2012 Olympics with so many applications scrapped.
He said the situation was "soul-destroying" and he partly blamed the government.
He said: "I'm really annoyed with them because I voted Tory as they backed the police, while the Lib Dems said they were going to recruit more police officers."
A different candidate told the BBC News website he had spent a long time working on his application and was delighted when he was told he had been successful, so the latest development was a real blow.
'Not enough vacancies'
He said: "If they wanted to cull us, they should have told us earlier."
Frustrated applicants have been discussing the calls on a number of police internet forums. They say they had been told they would be receiving confirmation letters later this week.
A spokesman for the 33,000-strong Met said: "We are just not accepting further applications at this time. This is because there are many fewer officers leaving the MPS than expected.
"We are personally contacting each candidate to explain that we have many more candidates than vacancies. This will not always be the case.
"However, it is unfair to keep individuals in the recruitment system when there is little prospect of them being able to join in the foreseeable future."
In February, London mayor Boris Johnson announced he planned to reduce the number of police officers in the capital by 455 over the next three years.