Last week, the Chronicle reported the attack after police appealed for information on two men accused of dragging a woman into a nature reserve and raping her.
But a frustrated Chief Inspector Joe Wrigley told us on Monday: "The rape didn't happen. I want to reassure the public that there are not two rapists at large, lurking in Central Park.
"We had the complaint formally withdrawn and we will investigate whether she should be prosecuted.
"I want this to serve as a warning to people – if you make false allegations we will investigate you and seek to prosecute."
Mr Wrigley said the rape became their main priority and that detectives were pulled off other cases to assist.
"We do devote a great deal of time and energy to these cases, including e-fits, medical examinations, taking evidential statements, seeking further witnesses, building up intelligence and so on.
"There is an awful lot of stuff. To find it has been wasted is so frustrating."
Police had also issued an e-fit of an alleged suspect.
Ch Insp Wrigley went on to reiterate that people should be careful, use their common sense and stay in well-lit areas when walking through Chelmsford's park, but said this false allegation has created unnecessary fear among the public.
He added: "I think it's quite safe to walk through Central Park at most times but you can never say never.
"People have suffered horrible crimes at the hands of horrible people, but when somebody makes false allegations, it affects perception of what an area might be like.
"It's just not on. Now we have to repair the damage to the community built up by this false allegation."
During the investigation into wasting police time, someone will have to calculate how much this operation cost the police.
"We spent many hours investigating the crime," said Mr Wrigley.
"The reasons for making such false allegations are many.
"I would guess some people do it to seek attention, or when they have done something and are afraid of telling the truth, like they had consensual sex and say they were raped, to prevent themselves from criticism.
"I would like to add that type of rape, where a stranger or strangers takes hold of a woman or man they have never met before and subjects them to rape, is extremely rare.
"The vast majority occur within a domestic violence scenario. Generally the perpetrator is known to the victim.
"But where people do have genuine complaints of crime we will pull out all the stops to investigate as fully as possible.
"I would not wish to discourage anybody from making a complaint where a crime has occurred."