One man from Luton and two others from Bedford were blackmailed after performing sex acts on Skype with a woman they met online.
The three cases happened between March 1 and March 10 and the offender is believed to be based abroad.
It is thought the woman built up a relationship with the men before encouraging them to strip and perform sex acts on Skype.
She then demanded cash otherwise she would post the videos online.
Beds Police are now investigatinjg and have issued a warning about internet safety.
Detective Sergeant Sandra Evans said: “We are urging everyone to be really careful about what they post online. Remember, once something has happened online, it is almost impossible to completely remove it so be careful what you share and who you share it with.
“Not everyone online is who they say they are and it’s easy for people to hide their real intentions, so we’d advise you only speak to people who you know in real life, and never send anything you wouldn’t be comfortable sharing with a wider audience.
“We are also appealing for anyone else who has experienced this type of incident recently to get in touch with us as they might have further information that could help us find those responsible.”
Anyone with information or wishing to report a similar crime can contact police on 101.