"I had no idea David was being pursued for so much money as he kept it to himself," Josephine said.
"The late payment and interest charges were horrendous and I believe the demand for so much money was the final straw."
The mum of two said her late husband had earned about $250,000 a year from his IT business, which was contracted by Government bodies such as the Ministry of Education.
But he hit trouble following an economic downturn and was unemployed for seven months before his death.
A coroner's report concluded there was no alcohol in his body when he died.
Josephine, who moved to Auckland with her children Matthew and Imogen after her marriage broke up, said the IRD decided not to pursue her for the debt because her husband had no money or assets and left no will. She had contacted the IRD to ask why so much debt had amassed.
She was told at the time of her husband's death the matter was closed. "It was only after five years that I was able to relook at the demand for $161,000 and decided I wanted some answers," she said.
"Although we were separated, he was a lovely man and a very good father. He went downhill very quickly after being pursued for money he could not afford to repay at the time."
A senior IRD manager confirmed Sharp had been contacted but a spokeswoman said it could discuss cases only with authorised people.
In May 2012, Paul Jenkins, 39, killed himself after being aggressively chased for child support which with penalties had risen to $53,000.
Eighteen years ago, air conditioning repair man Ian Mutton was found dead next to a note addressed to the Commissioner of the IRD.
Former Act Party leader Rodney Hide campaigned for the IRD to take a less aggressive stance on its collection practices. He said the system had improved since a parliamentary inquiry sparked by Mutton's death.
"But tax is nonetheless still onerous and tough for small businesses and contractors with uneven cash flow," Hide told the Herald on Sunday. "The penalties and interest charges are crushing for anyone who, through no fault of their own, falls behind.
"The fault lies not with the IRD but with politicians who demand that IRD squeeze until our pips squeak to fund their election promises."
Where to get help:
• Lifeline: 0800 543 354 (available 24/7)
• Suicide Crisis Helpline: 0508 828 865 (0508 TAUTOKO) (available 24/7)
• Youth services: (06) 3555 906
• Youthline: 0800 376 633
• Kidsline: 0800 543 754 (4pm to 6pm weekdays)
• Whatsup: 0800 942 8787 (1pm to 11pm)
• Depression helpline: 0800 111 757 (available 24/7)
• Rainbow Youth: (09) 376 4155
• CASPER Suicide Prevention
If it is an emergency and you feel like you or someone else is at risk, call 111.