Justin Evans, from Port Talbot, racked up the eye-watering debt over years of non-payment or fractional payment.
His former partner and mother of their 12-year-old son, Lisa Jones, accuses the Child Support Agency of failing to crack down on Evans despite a protracted battle to compel him to pay his dues.
"I pushed for months through the Child Support Agency (CSA) to get court action," Lisa, who works part-time as a beauty therapist, told Wales Online.
"Eventually it came to a point where he had letters sent to him saying court action was going to be taken unless he started making payments."
Yet, she says, after Evans made a nominal payment of £1, the court order was rescinded.
Local MP Peter Hain judged the case to be so egregious that he raised it in the House of Commons, telling fellow MPs of how Lisa's plight illustrated the CSA's 'lackadaisical' attitude to pursuing parents who fail to pay their share.
Hain warned that households like hers were being 'pushed into poverty' by the CSA's inaction.
"She's been left struggling on tax credits and housing benefit... while the father takes exotic holidays avoiding court orders," Hain told fellow MPs.
Work and Pensions Iain Duncan Smith said that it was 'outrageous' that Evans had been allowed to fall so far in arrears, saying that the 35-year-old had 'complicated' the matter by continually changing his address.
Since being publicly lambasted, Evans has stated that he intends to start regular payments. "I agree I haven't made a payment for a while now," he acknowledged, saying that he has now.
He says his ability to pay up is compromised by the fact that he has another child, a toddler, to support to the tune of £50 a week.
A recent report from the National Audit Office found that 29 per cent of non-resident parents pay nothing towards their child's upkeep, and only 35 percent pay 90 percent or more of the full sum due.
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