A Serious Fraud Office probe into one of New Zealand's largest privately owned construction companies - which involved raids on two premises and the seizure of computers - has been closed with no prosecution brought.
The SFO last August raided two premises linked to Hawkins Construction and the $419 million upgrade of Transpower's Hobson St substation, which the company was project managing.
Hawkins was contracted by Vector and Transpower in the substation redevelopment.
On the day of the raids, workers were sent home and security guards posted outside the project site.
But after an investigation involving the trawling of thousands of documents, interviews and industry experts, the SFO said there were no grounds for a criminal prosecution.
While parties investigated had conducted business in an "unusual" way, SFO acting chief executive Simon McArley said it was possible those involved believed their conduct was legitimate.
"In light of that it cannot be concluded that the criminal threshold has been reached," he said in a statement today.
The SFO said concerns had been raised in good faith but were not substantiated.