Fans were invited to enter a £20 raffle to follow the team on their pre-season tour of Hungary.
But the winning entry was later described as "not legitimate".
"After a thorough internal investigation, I can now confirm that the person responsible for this total farce has left the football club," said director Ashley Carson.
"Kevin Fitzgerald has been a hard-working, respected, likeable employee who has, for some reason, made a massive error of judgement and has subsequently paid the consequences for his actions.
"The board were unaware of his actions and have taken swift action after uncovering the truth."
The club apologised to supporters on Tuesday and said all other lotteries and raffles run by the club would not be affected by the incident.
"I do hope that we can look for a replacement to head our commercial department, move forward and pick up the pieces from the whole sorry mess," added Carson.