This would depend on the copyright status of the website and its content. In general, if you create something, you own the copyright unless you create it in the course of employment, in which case the copyright belongs to your employer - i.e. your former business. This would be separate from the copyright of the website itself which, depending on the details of the original contract with the web developer, may lie with the original company or the web developer. To muddy things more, that contract may have assigned or granted licences for some of the copyright (photos, text) owned by the company to the web developer.
Basically, if you own the copyright for something, you then have the right to allow it to be re-used. So, if the web developer owned or had a transferrable licence for everything on the website, they are perfectly at liberty to sell to the new owners again. Similarly, if the new owners received all the copyrights owned by the old business when they purchased it, they are, again, within their rights to re-use the website. If, on the other hand, you do own the copyright for anything on the website, and have not licensed it to the business (bear in mind that a licence to the old business might have transferred to the new business) you have a right to prevent them using it. Much of who owns what depends on the details of the contracts between you, your company and the web developer, as well as what happened to any assets (copyright is an asset) that may have been sold by an administrator, if there was one.
As you can see from the preceding two paragraphs, copyright law can be complicated. It's hard to tell if you have any claim from what you've posted (and IANAL anyway), so if you're serious about it, I strongly recommend you check with your solicitor (or at least a Citizen's Advice Bureau), who will know what contracts etc. to check, as well as knowing the details of Australian copyright law.
Also, you mention that you're in some of the photographs. In some jurisdictions, this can give you a "personality right" to object to the photographs, but this is nowhere near as universally-established as copyright. In Scots law, on of the limits is if you are "incidental" to a photograph, but I know very little else about how Scots, let alone Australian, law deals with this. Again, your solicitor or CAB can help.
