When Wells Fargo admitted a few months ago that thousands of its employees had created as many as two million unauthorized accounts for its customers, alarm bells went off at Prudential, one of the nation’s biggest insurance firms.

Wells Fargo has a partnership with Prudential to sell a low-cost life insurance policy to the bank’s retail customers. After news of the Wells Fargo settlement in September, Prudential ordered an internal review of its dealings with the bank, to make sure nothing was amiss with the joint endeavor.

A lot was amiss. According to three former managers in Prudential’s corporate investigation division, Wells Fargo employees appeared to have signed up bank customers for Prudential insurance without the customers’ knowledge or permission. In some cases, they even arranged for monthly premium fees to be withdrawn from their customers’ accounts.

When investigators reviewed tapes of calls to Prudential’s customer service line, they found complaints from Wells Fargo customers about policies they did not remember buying. Many of the customers did not speak English and needed a Spanish interpreter, the three plaintiffs said.