Pedestrians exit an escalator that runs past an electronic screen and ticker board that indicates stock figures at the Singapore Exchange Ltd. (SGX) headquarters.

Singapore-listed commodity trader Noble Group has become the latest target of a critical research report, sending its shares sliding, but this latest incident leaves many open questions about the report's author.

Iceberg Research published a report headlined "Noble Group, a repeat of Enron," and claimed more critical reports about Noble would be in the offing. The report alleges that Noble's accounting treatments were "unusual," result in "fabricated" profit and "intentionally misleads credit agencies and investors."