New Zealand Trade and Enterprise (NZTE) officials have warned Christchurch businesses to be wary of an extortion scheme in which executives are lured to China, only to be ripped off.

At least one businessman is understood to have fallen for the scam, ending up being forced to hand over money and credit cards after travelling to China for a dream deal that never existed.

Con artists are sending out authentic-looking tenders by email, offering firms the chance to produce a sample part that could lead to sizeable deals.

The firms are then asked to send a representative to China to sign a contract.

A Christchurch sheetmetal business, Davin Industries, was invited to supply what sounded like an "easy" quote a month ago.

Co-owner Peter McFaull said he initially ignored an email sent to his office, but then received a phone call from China.

The Chinese contact wanted him to meet in China to review a contract, and sent convincing product orders.

Mr McFaull has since heard of a business losing tens of thousands of dollars in the scam.

"From what we have heard, they get you in a room and extort money out of you," he said.

His company contacted NZTE officials, who warned him to have nothing to do with the businessmen from the southeastern Chinese town of Kunming.

Mr McFaull said his company was suspicious of the "coals to Newcastle" deal because China was a leader in cheap mass production.

He told other merchants of the scam before receiving another email this week.

"That second inquiry got me worried," Mr McFaull said. "New Zealand business needs to know that this sort of scam is out there."

NZTE international market manager for North Asia Jonathan Watt said companies should be aware of the potential dangers of email.

"Companies need to use due diligence and verify who they are dealing with, especially if they are dealing with companies through email alone," he said.

An Invercargill business, Crown Sheetmetal (CS), initially accepted an email on face value before approaching the Southland Chamber of Commerce, which warned it off the venture.

CS managing director Ross Young said the company gave a quote for a "sizeable job" because the tender looked genuine.

He said alarm bells rang when the Chinese did not want to see a sample stipulated in the contract.

Another warning sign was when a Chinese woman did not return requests for details of the company she worked for, he said.

The company provided a weak excuse that it was difficult for its staff to get out of China when told it made more sense for its representatives to come to New Zealand to see where the samples were made.

"They will get someone," Mr Young said. "I just hope the New Zealand companies are a bit brighter than that and check before they race over there."

He said the thought of having his credit cards and money removed was a "scary thing".

He would not have made the journey without being accompanied by a trade delegation, he said.

Canterbury Employers' Chamber of Commerce chief executive Peter Townsend said the Chinese email was a new one, but the chamber had a thick file of scams.

"Scams are alive and well and all over the place, and people have to be careful," he said.

"If something looks to be too good to be true, it probably is, and there are people using the internet in an absolutely unscrupulous way."

- nzpa