A check that Democratic New Jersey Sen. Bob Menendez wrote to his longtime campaign donor Dr. Salomon Melgen on Jan. 4 to cover private jet travel to the Dominican Republic represented more than one-third of his cash-on-hand — and perhaps as much as 90 percent — according to an analysis of his most recent U.S. Senate financial disclosure report.

Dan O’Brien, Menendez’s chief of staff, told WNBC-TV4 in New York on Tuesday that the senator reimbursed Melgen $58,500 for two trips they took together to the island nation in 2010. (RELATED: Menendez admits frequent Dominican travel, reimburses FBI-raided donor)

Menendez signed a disclosure statement on May 9, 2012 indicating that he had between $66,003 and $165,000 in three different bank and credit union accounts. His only other asset is a rental property worth between $250,001 and $500,000.

Financial disclosure forms filed by members of the House and Senate typically describe asset values in ranges, not precise numbers.

Menendez earns a $174,000 annual salary as a U.S. senator. Factoring in federal and New Jersey state income taxes, plus Social Security and Medicare withholding, the $58,500 check represents more than 51 percent of his expected take-home pay of about $113,000 during 2013.

His sudden reimbursement of Melgen came more than two years after the travel in question, and barely two months after The Daily Caller first reported the allegations of two prostitutes who said they were paid to have sex with him in the Dominican Republic. (RELATED VIDEO: Dominican women say Menendez paid them for sex)

Menendez has forcefully denied the prostitution-related allegations, which have expanded to include the accusation that he had sex with at least one underage girl at a sex party in one of Melgen’s Dominican homes.

The senator’s willingness to part with such a large amount of his personal funds also underscores the seriousness of charges he might otherwise have faced from the Senate Ethics committee.

Ethics rules require some combination of advance permission and after-the-fact reporting whenever senators accept significant job-related perks or gifts from friends, including free travel. But since Menendez elected to pay for the trips himself, he’s not obligated to report the transactions officially, and any investigative trail into other similar trips will likely run cold.

Meanwhile, federal investigators raided Melgen’s flagship eye clinic in south Florida Tuesday night in an operation that an FBI source told TheDC was related to Menendez in some way. (RELATED: Dominican prostitute wrote that Menendez “likes the youngest and newest girls”)

Melgen also owes the federal government more than $11 million in back taxes, and the Miami Herald has reported that he may be under investigation for Medicare fraud.

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