  It has been suggested that small chemical anomalies observed in
planet-hosting wide binary systems could be due to planet signatures, where the
role of the planetary mass is still unknown. We search for a possible planet
signature by analyzing the Tc trends in the remarkable binary system
HD196067-HD196068. At the moment, only HD196067 is known to host a planet which
is near the brown dwarf regime. We take advantage of the strong physical
similarity between both stars, which is crucial to achieving the highest
possible precision in stellar parameters and elemental chemical abundances.
This system gives us a unique opportunity to explore if a possible depletion of
refractories in a binary system could be inhibited by the presence of a massive
planet. We performed a line-by-line chemical differential study, employing the
non-solar-scaled opacities, in order to reach the highest precision in the
calculations. After differentially comparing both stars, HD196067 displays a
clear deficiency in refractory elements in the Tc plane, a lower iron content
(0.051 dex) and also a lower Li I content (0.14 dex) than its companion. In
addition, the differential abundances reveal a Tc trend. These targets
represent the first cases of an abundance difference around a binary system
hosting a super-Jupiter. Although we explored several scenarios to explain the
chemical anomalies, none of them can be entirely ruled out. Additional
monitoring of the system as well as studies of larger sample of wide binary
systems hosting massive planets, are needed to better understand the chemical
abundance trend observed in HD196067-68.
