Voxy News Engine Thursday, 11 June, 2009 - 15:46 Greymouth, June 11 NZPA - A West Coast woman falsely accused her sister's boyfriend of raping her in an attempt to conceal from her sister that she was sleeping with him, a court was told.

In Greymouth District Court yesterday Terri-Lee Bettjeman, 22, of Moana, 39km southwest of Greymouth, was remanded on bail for sentencing on August 24 after she admitted making a false complaint.

Judge Brian Callaghan told Bettjeman she was lucky she had not been charged with perverting the course of justice, warning that she would probably go to jail anyway. Bettjeman told police the man broke into her Westport house and raped her on October 27 last year.

Police took the allegations seriously and arrested the man who spent seven days in custody.

Bettjeman was examined by a doctor, who specialised in sexual indecency, and five officers were involved in a week-long investigation.

"The investigation finally revealed that the defendant was in a deceitful relationship with her sister's boyfriend and made up the false allegation to cover it up," police prosecutor sergeant Mark Harris said.

Police estimated the inquiry had cost $4100 and sought that amount in reparation.