Amateur prospector talks about 'surreal' moment he discovered $20k gold nugget in a West Coast creek bed

A West Coast man has quite literally "struck gold" while fossicking around a Hokitika creek bed this week.

Craig Douglas found one of the largest gold nuggets New Zealand has seen in around 40 years when he took his metal detector out for a walk on Monday. 

Mr Douglas told Seven Sharp how he reacted when he found the nugget.

"I used some expletives and stared at it for a moment not believing what I was seeing, it was surreal really."

The 6.25 ounces (177g) gold nugget has been valued at $20,000 and has already been bought by a Canterbury collector for an undisclosed sum that was below its valuation.

"Part of me wanted to keep it for a sentimental thing but decided the best thing was not to have it in my possession anymore," Mr Douglas said.

When asked exactly where he found the gold the amateur prospector said he would prefer to "keep it under wraps".