Complaints of internet fraud received by a US watchdog last year rose by 33% from 2007, its latest report shows.
The Internet Crime Complaint Center (IC3), which includes the FBI, received 275,284 complaints in 2008, which amounted to losses of $265m (£185m).
The most common complaint was non-delivery of goods followed by internet auction fraud and credit card fraud.
The IC3 warned that figures would probably rise through 2009 as the global economic downturn deepens.
Complaints in March alone rose by nearly 50%, said the report's author, John Kane.
"2009 is shaping up to be a very busy year in terms of cyber-crime," he said.
The IC3, a partnership between the FBI and the National White Collar Crime Center, said last year's losses compared with $239m (£167m) in 2007 and dwarfed the $18m (£12m) losses it reported in 2001.
The average amount lost by individual victims in 2008 was $931 (£652), it said.
Of those who complained to the IC3 in 2008, 66% reported internet crime originating in the US, followed by the UK in second place at 11%, Nigeria 7.5%, Canada 3% and China 1.6%.
In the US, most alleged scams originated from California followed by New York and Florida, the report said.
The IC3 report said 72,940 complaints were passed on to US law enforcement agencies for possible prosecution.
FBI Cyber Division assistant director Shawn Henry said the report illustrated that sophisticated computer fraud schemes were flourishing as more financial information moved to the internet.
"It also underscores the need for continued vigilance on the part of law enforcement, businesses, and the home computer user to be aware of these schemes and employ sound security procedures," he said.
Mr Kane, managing director of the National White Collar Crime Center, said the numbers could represent just the tip of an iceberg.
"Our own research suggests that as few as 15% of cases of cyber-fraud are being reported to crime control agencies," he said.
Statistics revealed in the report also showed that men lost more money in cyber-crime than women.
On average, for every $1 (70p) lost by women, men lost $1.69 (£1).
The report said the discrepancy could be due to different spending patterns by men and women on the web.