A former treasurer of Alcona County in Michigan has been arrested after allegedly investing more than $1.2m of county funds in Nigerian fraud scams.

Security firm Sophos said that Thomas Katona, who was treasurer of Alcona County for 13 years, has been charged with forgery and multiple counts of embezzlement. Both charges carry a jail sentence of 10 years or more.

It is reported that county treasury employees became suspicious of Katona's dealings after local bank officials informed them that he had directed several unauthorised transfers to overseas accounts during late 2006, including to beneficiaries linked with Nigerian 419 scams.

It was then uncovered that he had made further payments using his personal savings, and had previously been advised by bank officials that he was investing money in fraudulent schemes.

"Nigerian scam emails promise the world but deliver nothing in return for the cash that people continue to invest," said Graham Cluley, senior technology consultant at Sophos.

"Many people fall victim to email scams due to naivety, but in this case Katona was warned about the consequences of investing and decided to proceed regardless.

"There is not much that can be done to stop people who serve up their wallets on a plate to scammers, but clearly handing over your county's money cannot be tolerated, and hopefully this arrest will serve as an example to others."