German newspaper Süddeutsche Zeitung reported Mrs Wulff had given a sworn declaration denying all allegations relating to prostitution or escort work before her marriage.
The rumours have spread both online and in various media outlets.
It has been reported they were started in order to disrupt her husband Christian Wulff’s political career.
German newspaper Der Spiegel reports she has spent over two years fighting allegations she was once employed as an escort.
“Her lawyers have already issued 34 successful cease-and-desist orders, including one against a prominent German television personality this weekend,” the paper notes.
The same paper says a defamation suit was launched against Google last week.
Head of PR for Google Germany, Kay Oberbeck, said the site’s search terms were “algorithmically generated” and “include the popularity of the entered search terms”.
“All terms that appear have been previously entered by Google users,” he added in a statement.
The same text generates in rival search engine Bing.com.
In March 2012 Google was ordered to disable the autocomplete function relating to search results for an unnamed man in Japan, who said his name was being associated with crimes he had not committed.