A judge ruled the lies by Leonard Watters that the pop music mogul sexually assaulted him in a Dublin nightspot were so serious that she increased the jail term to 11 months, but suspended the last five.
Judge Katherine Delahunt warned that the 25-year-old must co-operate with the probation services and enter an alcohol rehabilitation programme on release or face going back behind bars.
“Alcohol and its abuse will never be accepted as an excuse for the commission of a crime,” she said.
“It could possibly be seen to go some way towards an explanation for events of the night in Krystle, but you publicly continued with the charade for two months until you were confronted by irrefutable evidence that you were lying.”
Watters, who wore a black suit and white shirt, showed no emotion as he was taken away by prison guards from the Circuit Court in Dublin.
The father-of-two falsely accused Walsh of sexually assaulting him in the toilet of the celebrity nightclub, Krystle, after a Westlife concert in April 2011.
Two months later he made two official reports to the police and went to a tabloid newspaper, which printed a story before Walsh was questioned under caution.
Within days, Watters was shown CCTV footage that disputed his claims and he admitted making up the allegation.
“Your main problem is one of alcohol and its abuse,” Judge Delahunt said.