Keydatavictims has been taken offline after allegations of libel by Keydata founder Stewart Ford.
In a statement, Ford's spokesperson Jack Irvine said contributors to the site had made "repeated defamations" of the character of the former director of the failed investment company.
False allegations about Ford's motivations over the last few months had also been posted, he said.
The website was set up as a forum for investors and IFAs affected by the collapse of Keydata Investment Services to share information.
Key discussions centred on what led to the FSA putting the firm in administration in June 2009, ways in which investors could reclaim their capital, and who was to blame for their loss of income.
Irvine says no legal proceedings have been been started to close down keydatavictims.nig.com.
But the site's internet service provider (ISP) took it offline on Friday after Ford's lawyers complained contributors had made "highly offensive allegations" about his family.
Ford's lawyers have also written to the website's creator and moderator Peter Magowan to complain of "false and defamatory material" being posted on the site.
Magowan was unable for comment.
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