The News of the World says Klinsmann's representatives contacted Liverpool officials to warn them that Benitez's early transfer plans had been passed to their man.
The club were stunned to discover Klinsmann's view was sought on the quality of at least one target they are in the process of scouting.
The revelation will antagonise boss Benitez, who has sent private e-mails to co-owner Hicks outlining the players he wants to recruit for a title assault next season.
A source close to Hicks insists "to their knowledge" there has been no contact between the co-owner and Klinsmann for months. If so, that will leave Benitez baffled as to how Klinsmann knew the contents of his e-mails.