The seller, who lives south of Perth, then received a fake PayPal email falsely confirming the funds had been deposited.

The scammer then asked the seller to help them by paying shipping charges and customs duty.

The victim received fake Nigerian Customs forms and phony PayPal emails again confirming the additional freight money had been deposited by the buyer.

Suspecting a scam, the woman called Consumer Protection which told her to stop dealing with the fraudsters.

Upon forwarding this email to the scammers, she then received fake emails back from them featuring WA ScamNet and WA government logos, which advised her to co-operate with Nigerian authorities.

Commissioner for Consumer Protection Anne Driscoll said she was alarmed that overseas scammers were becoming more professional and determined.

"It's a major concern that phony emails purporting to be from Consumer Protection's WA ScamNet service were used in this scam," Ms Driscoll said.

"These criminals will stop at nothing to fleece online buyers and sellers of their money, including impersonating government officials in fake emails, and it's almost impossible for the money to be recovered once transferred."

The hoax escalated when the woman received a phony eBay email saying the case had been reported to Nigerian Police who then emailed her to say that the fraudster had been arrested.

Later, the fake police email told her that the courts and president of Nigeria had awarded her compensation amounting to $US250,000 ($278,000).

"We are putting in all efforts to erase the bad name given to this great country of ours," the scammers, posing as Nigerian police, wrote in the email.

"The President is making sure that victims of fraud are compensated."

A false document supposedly from the Nigerian Central Bank was then received, confirming the money was awaiting transfer to the woman's bank account.

However, she had to pay a transfer fee of about $US7000 ($7800) before the money could be released.

After losing about $8700 in total, the single mother took her case to Consumer Protection offices in Perth and was told she had been conned.

She told Consumer Protection staff she felt "violated" by the scam.

"If we go on eBay again, I'm not selling anything to overseas," she said.

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"This is our first time and it's my last time.

"Never again, never again."