A Western Australian man who lost about $700,000 to offshore scammers says he was expecting to inherit $26 million.

The man in his 70s, who wishes to remain anonymous, says he sent the money offshore over a period of years as part of an inheritance and investment scam.

The Major Fraud Squad said they alerted the man a number of times but he continued to send money overseas.

Officers says it is the highest loss they have recorded as part of Operation Sunbird - a project aimed at eradicating the crime.

He says he feels foolish but is speaking out to help others.

"There was supposed to be $26 million left to me by an old lady in London," he said.

"I actually, supposedly paid the Spanish government $46,000 tax on that."

He says people need to be incredibly wary of internet fraudsters.

"It's all very, very cleverly thought out," he said.

"I'm just an average guy but these guys, they are honest criminals, as crook as you can get."

The man says he hopes to save somebody else being ripped off a lot of money.

"They're very cunning - what they do is they say if you pay this, we'll release funds and you pay that," he said.

"It'll be a small fee for this and then we'll release it and, oh look, there's another fee and you pay that and this one's got to be paid, all these different fees."

In the past two months, 17 people in Geraldton have sent about $1 million to fraudsters in west Africa.

Police says they are sophisticated crimes that can have a crippling impact on lives.

WA Police and the Department of Commerce hosted a forum in Geraldton on Wednesday evening to raise awareness of the issue.

The department's Danni Bloomfield says it is the first time an event of its kind has been held in regional WA.