Californian authorities were totally unaware the construction firm which developed the Berkeley complex at which six students died had paid out €23m ($26.5m) in lawsuit settlements in just six years.
The revelation came as three investigations are now underway in San Francisco into the Library Gardens balcony tragedy on June 16 in which six students died and seven were injured.
Five of the dead were Irish.
Two Irish students remain in a critical condition in Berkeley hospitals.
Alameda County District-Attorney Nancy O'Malley is now conducting twin civil and criminal investigations into how eight timber balcony beams in a complex only eight years old could severely rot and then fail catastrophically.
A third probe is being conducted by the Contractors State License Board (CSLB), the body charged with regulating all builders operating in California.
The CSLB regulates 300,000 construction firms and sub- contractors.
However, the board was totally unaware of the fact Segue Construction had paid out €23m ($26.5m) in lawsuit settlements over the past six years.
Several of those settlements involved claims for damage related to water leaks.
In two cases, San Jose and Millbrae, the damage claims involved timber balconies.
Segue insisted those lawsuits are totally unrelated to the Berkeley tragedy.
The firm, which obtained an operator license from CSLB in 1992 and renewed it last year, insisted it is co-operating fully with all ongoing investigations.
The sub-contractor which undertook the waterproofing work at the Library Gardens complex, R. Bros, is also co-operating with the various probes.
It remains unclear what action, if any, will result from the triple investigation.
However, Ms O'Malley's criminal investigation does have the power to initiate charges of up to involuntary manslaughter.
The CSLB is now demanding that rules be changed so that it is formally notified of all lawsuits settlements.
CSLB director, David Fogt, confirmed they were unaware of Segue's €23m lawsuit settlements. "We didn't know - that is a problem. Somebody has to let us know about it," he said.
"It is troubling that we did not (know). We had no prior complaints.
"There is nothing in place that would notify us of a lawsuit."
"Any allegation of a contractor having poor workmanship or acting out of compliance of building code requirements is taken very seriously by the contractors' board," he said.
The CSLB only became aware of the scale of Segue's lawsuit settlements in the wake of the Berkeley tragedy.
Details of two of Segue's lawsuit settlements only became public because confidentiality clauses were not attached to the legal agreements.
The CSLB said it would have been very interested in the settlement details because of their sheer size and the nature of the allegations involved.
"Any lawsuit that relates to allegedly defective work that results in the contractor paying damages would be of great interest to us," Mr Fogt told the 'San Francisco Chronicle'.