Nigerian authorities have started trying to reduce a notorious homegrown type of Internet crime. These e-mails, familiar to many Internet users, have started embarrassing Nigeria's government.

"URGENT ASSISTANCE" screams the subject line of one recent e-mail sent from Nigeria to thousands of computer users around the world.

The sender, who says his name is Mohammed Abacha, says he is a relative of Nigeria's former military ruler Sani Abacha. He says he needs help to retrieve some hidden money.

He also includes his phone number and gives the same account of his proposed deal over the phone.

The funds are deposited in a security company in London so I do not know if you can travel to London and get these funds for me. It has been deposited in two trunk boxes, which the company does not know its content. I am going to give you 20 percent of the total of these funds. The total is $25 million.

He says releasing the boxes might be complicated, which means it might require an advance fee from whoever will help. This is when the fraudsters start asking for bank account information.

But the man who calls himself Mr. Abacha denies he is operating a scam.

I am going to send you my family pictures and every necessary document regarding this transaction. This is not a scam.

The chairman of Nigeria's newly established Economic and Financial Crimes Commission, Nuhu Ribadu, disagrees. He says all such e-mails are criminal fraud and they hurt efforts to build investor confidence in Nigeria. "They have done so much damage to us. It has really dented our image and credibility. We feel that this is one thing that we just have to face and solve," he says.

Mr. Ribadu says since last year his commission has carried out investigations that led to the arrest of more than 200 cyber-criminals, of which about 100 have been sentenced to jail.

The government is also planning a global advertising campaign to warn potential victims.

Mr. Ribadu says victims should not be afraid to cooperate with Nigerian authorities, once they realize they are being conned. "We treat people as victims. We do not look at anybody as a co-conspirator or anything like that. Of course, some people might say it is greed that might lead them to that, but greed is not an offense anywhere in the world," he says.

Because of this greed, Nigerian officials say some of the victims have had their bank accounts completely wiped out.

Nigeria's biggest fraud case is in the courts. Three people are accused of defrauding a Brazilian bank of $242 million, and their lawyers are accused of trying to bribe Mr. Ribadu, the chairman of the financial crimes commission, using bags full of cash.

Widespread fraud and corruption in Nigeria have drawn criticism from several international organizations, including Transparency International. Nigerian President Olusegun Obasanjo is a co-founder of the group, but it criticized him for not doing much to fight corruption since he returned to power in 1999.

But since his re-election last year, Mr. Obasanjo's government has launched several high-profile corruption cases, as well as the effort to crack down on all types of fraud.

A spokesman for Transparency International, Tunde Olugboji, says he is impressed with the Nigerian government's new effort. "I think if they continue on this track then I think there is a very huge possibility that the image of the country could be changed around for the better if they continue this way with this vigor. To be very honest I think it is becoming a bit of an embarrassment to government," he says.

Other governments may soon need to draw on Nigeria's experience. This type of e-mail fraud has been copied elsewhere - from nearby Sierra Leone and Liberia to the faraway Philippines - where fraudsters also say they have access to millions of dollars from previous corrupt governments. All the claims are false, of course, but some Internet users still believe them.