Colin Farrell dated a fake woman on the web according to an explosive new report from Who's Dated Who.

The site says Farrell dated fake woman "Bree Condon" sometime over the past two years. And we can only presume this was before his relationship with his co-star Alicja Bachleda (above) took off.

"Bree" passed herself off as a 23-year-old Guess and Maxim model from Newport Beach, Calif. However, there was just one teeny little problem. This "Bree" is actually a man; Justin Brown in fact while the real-life Bree was furious that someone was impersonating her.

The scam was revealed when Real Bree (who is a model for Maxim and Guess) hired a private investigator to find out who Fake Bree was.

The PI found Fake Bree/Brown holed up in a motel room in Austin, Texas with gifts and pets from would-be suitors.

Turns out that Fake Bree/Brown had created an entire persona on the web and sought dates through the website www.seeking millionaires.com.

Apparently, none of the wealthy love-lorn ever got to meet Fake Bree. (For obvious reasons!)

But the site says they engaged in "intimate phone conversations" and swapped nude photos.

No word on whether Colin engaged in "intimate phone conversations" or swapped nude pictures with Fake Bree/Brown.