The hosting company, which has been offline now for 12 days, has also had its phone line disconnected.
iTnews understands the company had been forced to issue a new support number after the outsourced customer support service it was using, Web Hosting Support, cut them off in mid-December.
"We've had quite a lot of calls for them from people chasing money," a spokesperson for Web Hosting Support said.
"We closed down their service quite a while ago due to similar issues. We haven't had too many calls since their website got shut down."
Web hosting providers Hightek Hosting and Crucial Paradigm are also understood to have been affected by the apparent closure of Dedicated Host.
Both provided wholesale capacity to the company in Melbourne and Sydney respectively.
A Crucial spokersperson said: "They're no longer a client. We cut them off."
A spokesperson for Hightek Hosting confirmed to iTnews that the company provided wholesale capacity for Dedicated Host in Melbourne.
"We were a wholesale provider for them [but] I can't tell you much more as to the current business relationship," the spokesperson said.
"We cannot comment any further as to their current position with our company."
The spokesperson said Hightek Hosting was open to transitioning customers of any web hosting provider or reseller that is having difficulties across to its own services.
"For support purposes, we don't like other people's customers contacting us and saying ‘help us', but if you're having difficulty, then we're more than happy to move you from anywhere," the spokesperson said.
"The offer isn't specific to Dedicated Host customers. If you're having problems with a particular provider then we're more than happy to transfer you."
Users of the Web Hosting Talk forums have advised customers of Dedicated Host to move to an alternate provider.