The Australian Federal Police say they worked "tirelessly" for more than two weeks to locate 12 women who had been trafficked to Australia to work as prostitutes - before finding out it was a hoax made up by a Mandurah resident.
Last week, the Mandurah Mail reported on the incident that cost "tens and thousands of dollars", according to police prosecutor Sean Discombe.
Ravenswood woman Elaine Anne Gilhespy, 55, was sentenced to a community order in the Mandurah Magistrates Court on March 12, after pleading guilty to making seven hoax calls to triple zero.
The Australian Federal Police takes human trafficking allegations very seriously.
Gilhespy called police and said she was being held against her will in an unknown location with 12 other women, including one 14-year-old, prompting an investigation, Operation Arakiss, involving several organisations working together including the Australian Border Force.
Detective Superintendent Timothy Underhill said the operation was "heavily supported" by WA Police, in particular, Mandurah Detectives.
"As the lead agency for human trafficking investigations, AFP members worked tirelessly for 15 days to try and locate the alleged victims," he said.
"While it is disappointing such a hoax was committed, our ability to locate and then assist WA Police in prosecuting the offender, is a credit to our ongoing working relationship."
An AFP spokesperson said the investigation required "significant resources".
"The AFP takes human trafficking allegations very seriously and will work collaboratively with our domestic partners to investigate and prosecute those responsible for human trafficking offences," he said.