Neither Ms Hegarty nor Fullers was able to confirm a report that alcohol was involved.
But the Fullers general manager for service delivery, Warren Fowler, said the antic was extremely dangerous as it happened after the large ferry had made a turn and was about to reverse to its berth.
"It could have been tragic with vessels coming in here and someone jumping off the back of a vessel when it is going to be reversing shortly," Mr Fowler said.
It is not the first time during the Rugby World Cup that Tuilagi, who plays at centre, has run into trouble.
This month, the International Rugby Board fined him $10,000 for wearing an unapproved mouthguard carrying the name of a sponsor.
His brother, Alesana Tuilagi, a winger for the Samoa rugby side, was fined the same amount earlier for wearing the same type of mouth-guard.
Tuilagi is not the first England player to get into hot water.
Former captain Mike Tindall was in strife after security camera images showed him cavorting with an ex-girlfriend.
England team managers could not be reached for comment last night.