The FMA ordered General Equity to display the regulator's warning on the building society's website, which has since been taken down and is listed as "under construction".
General Equity - according to its latest annual report on the building societies register - provides banking, structured finance, issuing of trade credit instruments and other financial services.
It said its main source of income in the 2013 financial year was derived from the Asset Builder Fund No 1 (ABF1), which the society claims it manages.
The FMA believes General Equity made "misleading and deceptive" statements in connection to the ABF1, which the society last year said had audited assets of US$6.2 billion ($7.9 billion) as at June 2012.
"In FMA's view, the ABF1 does not hold the assets General Equity claims it holds and was used by General Equity to give a misleading impression of adequate asset backing to support the issuance of letters of credit by General Equity," the regulator said.