The box arrived at his home in Italy and, when he opened it, the insurance executive was chilled by its contents: nine bullets, one each for him, his wife and their seven children. Sent by "persons unknown," the package is one of the more lurid elements of an international saga of private eyes, secret recordings and claims of bribery.

AmTrust Financial Services Inc., a New York-based insurer, describes the episode in a U.S. lawsuit against a former business partner in Italy after a deal went sour. The company says its Italian chief received the bullets though it doesn’t name the sender. AmTrust does, however, contend that its spurned ex-partner stole data, tried to poach staff, demanded more than 1 billion euros ($1.13 billion) it had no right to, and then bribed an arbitrator.

The allegations are contained in a  lawsuit filed in federal court in Manhattan this month and suggest that doing business in Italy, which ranked the worst of any Eurozone member in  Transparency International’s 2015 corruption index, is not for the faint-of-heart.

Antonio Somma, whose company was once AmTrust’s exclusive insurance broker in Italy, is accused of bribing Marco Lacchini, president of two arbitration panels in Milan. The alleged goal was to get him to issue rulings forcing AmTrust to pay hundreds of millions of dollars to settle a fight over the early termination of their business relationship. AmTrust, which has expanded to 20 countries and more than $17 billion in assets since its founding in 1998, says Somma offered Lacchini 10 percent of the final award.

Posing as Chinese Investors

In its New York suit against both Somma and Lacchini, AmTrust says it hired private investigators who posed as middlemen for Chinese investors and recorded Somma bragging about the alleged scheme. Separately, it says, the investigators taped Lacchini describing his ability to assure "amazing results" in arbitration.

Somma, 54, denies the claims, accusing AmTrust of seeking to delay the arbitration and fabricating evidence.

"I am flabbergasted," Somma said when reached for comment. "All allegations against me are groundless and even scandalous." He said AmTrust would pay for the damage it was causing.

Lacchini, 50, declined to comment when reached by phone. Neither has yet responded in court.

Michael Carlinsky, AmTrust’s lawyer with Quinn Emanuel Urquhart & Sullivan LLP in New York, said Somma’s claim that AmTrust faked evidence "is untrue and reflects Somma’s desperation." AmTrust had $6.8 billion in gross written premiums in 2015, an increase from $2.2 billion four years earlier, regulatory filings show. In 2009, the company began underwriting medical malpractice insurance in Italy and in 2012 opened its Italian branch which now generates 5 percent of its premiums.