More than $3 million in contributions backing an added slot-machine casino in Massachusetts came from offshore entities and their overseas employees in Asia, according to revised disclosures that deepen the mystery of the financial interests behind the gambling initiative.

Until the November 2 revisions, $1.5 million in contributions to the Horse Racing Jobs and Education Committee, which promotes the initiative, was listed in state campaign finance records as originating with Delaware-based Capital Productions LLC. The only other money reported in support was a $450 contribution from Eugene McCain, the Revere, Massachusetts, real estate developer who founded the committee.

Now, Capital Productions has disappeared from the campaign records. The revised filings have the same dates and sums for the $1.5 million, but replace Capital Productions with entities and individuals in Japan, Cambodia and the western Pacific island of Saipan, a U.S. Commonwealth territory.

These out-of-country parties have contributed an additional $1.7 million, according to the latest campaign filings. The committee’s filings do not elaborate on any interests these entities and individuals might have in passage of Question 1, and attempts to reach them have been unsuccessful.

The filings indicate that more than $1.2 million came from Bridge Capital LLC, an investment banking and asset management company on Saipan, which is part of the Northern Mariana Islands. The company also consults for companies “involved in commercial and residential real estate, land development, banking and loan origination,” according to its website.

In a February report submitted by McCain in his role as both chairman and treasurer, the campaign committee attested that Capital Productions contributed $284,000 in four installments. The revised report now attributes each of the cash contributions — as well as two in-kind contributions — to Bridge Capital.

An early September filing now reflects that more than $145,000 in contributions came from Regent Able Associate Co., a small consulting company based in Japan, rather than from Capital Productions. The listings further indicate that these funds came through a Miami-based company incorporated in March.

Subsequent reports indicate that both Bridge Capital and Regent Able Associate contributed to the committee via Miami Development Concepts, LLC. To date, Regent Able Associate has given more than $1.5 million to the committee via the Miami company. In addition to its direct contributions, two of Regent Able Associate’s employees also contributed directly.

Toko Kobayashi of Japan and Sok Chenda of Cambodia, both real estate developers for the company, each contributed $200,000 to the committee in October. The only contribution that matches the date and combined sum of their funding was previously attributed to Capital Productions. A video uploaded to the committee’s “Yes on 1” YouTube account on November 3 mentions Bridge Capital, Regent Able Associate and the two real estate developers as its “top contributors,” as does the campaign website.

Two promotional videos uploaded earlier do not contain any contributor listing. Jason Tait, a spokesperson for the state’s Office of Campaign and Political Finance, said he couldn’t comment on why the previous filings didn’t disclose the offshore entities or contributors. McCain and his lawyer did not return calls seeking comment.