"There were several discrepancies in her statement, which we informed her. She then told the police that he wanted to change her earlier statement," Joint Police Commissioner (Crime) P K Ghosh told reporters.
The police found that the victim, an ayah, was present at her place of work on Sunday, the time claimed she was gangraped after being picked up in a car, he said.
The police also found none in the locality, from where she claimed she was picked up, corroborated her statement, Ghosh said.
"She made a change in her statement, the reason for which is not known to us. But she did not tell us it was changed under duress," he said.
Ghosh, however, did not specify what the change in the statement was.
To a question, Ghosh said that the police would proceed with the case in line with the changed statement.
A person was earlier arrested on basis of the woman's complaint, he said.