Speaking outside Dublin High Court, Louis Walsh said he would not have wished what happened to him on his worst enemy.
"I'm very relieved," he said.
"This has had a terrible effect on me guys. It was all lies.
"And I'm very satisfied with this total vindication for me, but I remain very angry at the treatment I received at the hands of The Sun."
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The arrests were made on suspicion of producing and disseminating pedophilia content on the internet, the country's Justice Ministry said.
The A4-sized sketch originally went for £75 when it was first sold.