The Securities Commission says it has now banned an investment statement from a company named IRA NRG NZ Limited (INNL).
The move comes after the regulator "banned" the company's website earlier this month.
Securities Commission chairman Jane Diplock said INNL had made an illegal share offer to the public with no prospectus registered.
"The public offer of shares by INNL is illegal as there is no prospectus," said Diplock. "Any purported allotment of shares to investors would be void and of no effect. People should not invest in this company until it complies with the requirements of the Securities Act 1978."
In its previous announcement the Securities Commission said it had banned INNL's website and removed its content. The website had described INNL's plans to generate electricity and sell it to the national grid. The regulator said the website included claims of future income that weren't substantiated.
"There were no assumptions disclosed relating to the prospective financial information as required by law."