Thieves hacked their way through the awning, dumped it on the ground and hooked up the caravan and drove off from behind International Yacht Services on Riverside Dr, between Sunday night and Monday morning.
Treasured photo albums, jewellery and passports, plus most of his clothes, were all in the 4.5m cream-coloured Swift Cornich caravan that had been Mr Welsh's home for the past year.
Mr Welsh, who is working with Steve Bowling Contractors, revealed he has no insurance and the loss would cost him at least $20,000.
He had returned home early to Northland last year after a 35-year stint in Australia.
Originally from Te Kopuru near Dargaville, Mr Welsh said he had returned to New Zealand to catch up with friends and family. During his time across the ditch he said he had never had anything stolen.
His partner Ainslee Scott from Australia arrived this week to learn about the theft.
"Everything he had was in that caravan and all his personal stuff like photos on the computer. The whole invasion of his life, it's just sickening," she said.
Mr Welsh said the caravan was part of their retirement fund. They were working on converting a bus and were going to sell the caravan, which would have enabled them to put the finishing touches on the bus they planned to tour New Zealand in.
The couple are staying at a cousin's place while she is touring Europe, but will have to move in to the unfinished bus in two weeks when she returns.
Anyone who sees the caravan should call police on 09 430 4500.