Lotto players claimed they spotted a fix in Saturday night's £4.5million TV draw after a ball appeared to have two different numbers on it.
Stunned viewers were perplexed when they thought the say the red number 38 ball also having a number 33 printed on it.
When the ball was revealed during Ireland's Lotto Plus 1 draw on Saturday evening, viewers were quick to spot it and questioned whether it was a "fix", the MailOnline reported.
But organisers today dismissed the claims and simply said it was an "illusion" caused by a "brief reflection of light".
Live footage on RTE showed the ball roll into its slot after being drawn as the second number.
Footage from last night showed the number 38 ball with a number 33 on it - but the Irish National Lottery said it was caused by a 'brief reflection of light'.
When it came into shot, viewers were able to see the number 38 printed on the ball several times.
But they were left perplexed after seeing what they believed was a number 33 in the middle of the ball.
The 38 ball was drawn along with 1, 4, 29, 45, 46 and the bonus ball, 26.