The Blade Runner is said to have viewed at the X-rated material on his mobile phoneme which was recovered at his home in Pretoria where Reeva was killed.
A court document reportedly shows that he had looked at porn and used car websites "in the hours before" he shot his girlfriend, according to reports in the South African media.
The papers allegedly say: “The accused’s website activities from the time they were at home is in direct contrast to that of a loving couple spending time together.”
The reports come two days after it was claimed neighbours heard screams in between gunfire on the night Reeva was killed.
Court documents suggest a final round of shots "extinguished" the screams, it is believed.
On Valentines Day in 2013, Pistorius is alleged to have shot his model girlfriend four times through a locked bathroom door of his home in a gated community.
The Paralympain denies the charge of murder and says he thought his girlfriend was an intruder.
The trial begins on the 3rd March 2014.