A group of Latin American former clients of Stanford Financial Group have filed a lawsuit against Willis Group Holdings, the giant insurance broker, claiming that it aided in Stanford’s alleged $7 billion fraud. The lawsuit is seeking class action status on behalf of over 1,000 plaintiffs and asking for $1.6 billion in damages.

The clients say that the Willis Group illegally vouched for R. Allen Stanford, the owner of Stanford Financial Group, in letters he sent to his customers, according to a report by Bloomberg News. The complaint alleges that Willis acted as a sales agent for Stanford Financial, crossing the line of being solely an insurance broker.

All of the plaintiffs in this case are from Venezuela. A previous, similar case was filed on behalf of former Mexican clients of Stanford.

A spokesperson for the Willis Group told the New York Times that “it did not suspect any of its workers knew of fraud at Stanford” and that the company will “defend itself vigorously.”