Lou Burrows, the agency's human resources consultant, has seen security camera tapes from an internet cafe identified as the source of the email but failed to identify the culprit.
Lace, who claims not to have viewed the tapes, denies any plans to set up a loyalty scheme with Drew Thomson, the managing director of Air Miles, a Grey client.
Last week it was reported that Police were close to identifying the author of a hoax email implicating Lace.
Inquiries established that the email was sent from an internet cafe in London's Tottenham Court Road on the afternoon of Saturday February 7. Lace financed the hunt for the terminal that sent out the email out of his own pocket.
The footage was relatively easy to secure because internet cafes are currently being monitored by security cameras owing to the heightened threat posed by Al Qaeda terrorists, who are known to use internet cafes for their communications.
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