Reports have emerged that there was a heated confrontation in the Bulldogs dressing room after their 20-4 defeat to arch rival Parramatta at ANZ Stadium.

Rugby League reporter Josh Massoud reveals Bulldogs prop David Klemmer was approached by a man in the team's dressing room after full-time.

The man abused Klemmer with words to the effect of, 'You're a sh*t player, you can't even offload.'

Klemmer was angered and challenged the man. 'Could you do any better?' he fired back.

Klemmers young family helped diffuse the situation when he walked them out of the dressing room.

Bulldogs CEO Raelene Castle was in the room at the time of the incident and confirmed the club had no issue with Klemmer's behaviour.

The man was wearing no team colours and officials are trying to determine his identity.

The NRL recently introduced strict protocols around dressing room access, but these new policies become difficult to enforce after full-time, when venue security have finished their shift and players are still inside.