Trade Me is warning members to look out for signs of scammers trying to get details of their identities.
Criminal scammers from all over the world are now targeting Trade Me users on a daily basis, using fraudulent emails.
The site's Head of Security Jon Duffy says there are several warning signs to look for.
"If you get an email that looks like it's from Trade Me, and it says you need to log in because your details were lost or the file's been corrupt or something like that, you should immediately be suspicious."
Jon Duffy says so far no Trade Me members have lost money through internet scamming.