On the very same day Menendez interceded with Obama administration officials on the ports deal last summer, he also went to bat for another company involving a heavily disputed Dominican road-building contract. A deal, records show, that benefited New Jersey investors who contributed to his campaign.

The road contract, which has attracted scant attention in the United States, involved a firm called Codacsa, a Spanish consortium with U.S. interests, various government records show. At a hearing on July 31, 2012, of the Foreign Relations Subcommittee on the Western Hemisphere — then chaired by Menendez — the New Jersey senator called on the U.S. government to pressure the Dominican government on behalf of Codacsa in connection with a $42.5 million international arbitration award, according to an official transcript of the proceeding.

After fighting the Dominican government for years over a contract it won in 2001 for two big highway projects, Codacsa had won the arbitration award in January 2012, but had no way to collect the money.

Menendez, a Democrat, told officials from the State and Commerce departments that countries needed to be sent a message that they could not violate trade agreements and arbitration awards. "If these countries can get away with it, they will," he said at the hearing, according to the transcript.

A Star-Ledger review of court documents and public records in the Dominican Republic shows that the lone U.S. investor in Codacsa is a New Jersey company named Clearly Tropical. After revving up and winding down its investment over the years, the Fairfield, N.J.-based company had a $130,000 stake in Codacsa in 2012.

State corporate records show the company is headed by Ruby Pacheco, who — with her husband, Joseph Bonanno — have donated $19,800 to Menendez's campaigns and leadership PAC since 2006, according to Federal Election Commission records. Their most recent contributions came this past June, with two $2,500 checks to Menendez's November re-election campaign.