Queensland Police are warning against a new scam that promises investors gold and diamonds.

At least 52 people already have been duped out of a combined sum of nearly $2.5 million, police said.

They were promised high returns by investing in sporting events, iron ore, a gas pipeline, gold and diamonds with little effort.

Police allege the Gold Coast based scammers used false identities and qualifications to set up a hoax company used to trick the investors.

An investigation, code named Operation Echo Bargain, was launched in 2006 and has so far led to two arrests this year, with more to come, police say.

The first arrest was made on March 4, when a large sum of cash and two handguns were discovered when police searched a Parkwood home.

A 58-year-old man was charged with 27 counts of fraud totalling almost $1.4 million. He also faces charges of unlawful possession of a weapon and possession of tainted property and is due to appear in Brisbane Magistrates Court next week.

The second co-accused, a 59-year-old man from Ormeau Hills, was charged on April 1 with 27 counts of fraud totalling almost $1.4 million and will appear in Brisbane Magistrate's Court on May 17.

Detective Superintendent Brian Hay, of the Fraud and Corporate Crime Group, said the scam highlighted the "absolute importance of doing your homework before handing over your money".

"If someone contacts you by phone and makes grand claims of how quick and easy you can make money, you must do your own checks," Mr Hay said.

"Do not take at face value the claims of someone over the phone or the internet - seek independent advice from a third party.

"We are often called to investigate these so called get rich quick schemes - where participants pay high fees and have their money, which is often 'invested' in sporting outcomes or risky mining ventures, locked away for long periods of time.

"I cannot remind the community enough how important it is to be vigilant and never commit money to people cold calling you without thoroughly checking their credentials and where your money is going.

"When presented with an opportunity, don't get excited - get advice."

Fraud victims can contact the Fraud and Corporate Crime Group or report the matter online at www.police.qld.gov.au.

Anyone with information about fraud crime is urged to contact Crime Stoppers on 1800 333 000.