At the time, Chevron's attorneys, including Gibson, Dunn & Crutcher's Theodore Boutrous, and attorneys for the plaintiffs, including Patton Boggs' James Tyrrell Jr., declined to speculate about Alito's recusal. The justice didn't offer an explanation.

Alito last year didn’t participate in the high court's review in Chevron v. Naranjo, a dispute in which Ecuadorian natives are seeking damages against Chevron for allegedly polluting the environment.

Alito's report , at 23 pages, details numerous investments and trusts that include Chevron Corp., AT&T, Verizon Communications, Pepsico and Abbott Laboratories, to name a few big-name companies. (The justice's previous report, covering 2011, ran only eight pages.)

Justice Samuel Alito Jr.'s latest financial disclosure report, publicly released this afternoon, offers some potential insight into why he recused in a handful of high-profile disputes.

Alito's latest financial disclosure report, covering 2012, reveals he received a dividend, under $1,000, from Chevron. Alito reported the gross value of the asset at between $15,001 and $50,000.

Alito also recused from the high court's review of so-called "pay for delay" deals between brand-name and generic drug manufacturers. The Supreme Court in June, voting 5-3 in Federal Trade Commission v. Actavis, determined that the deals—in which generic companies receive money from brand-name makers in exchange for delaying production—do not presumptively violate federal antitrust law.

The latest financial disclosure report shows that Alito received dividends from pharmaceutical companies Abbott Labs and Merck & Co. Alito also reported a transaction that involved Bristol Meyers Squibb Co.

Alito recused last October from the court's assessment of Hepting v. AT&T. The Electronic Frontier Foundation, in that case, sued the telecommunications company over allegations of collaboration with the government in the monitoring of communications. The high court denied review.

Alito reported buying in December 2012—and then selling shortly thereafter—AT&T assets. The justice also reported selling Verizon assets.

Justices regularly make a few extra bucks on the side. Alito, for instance, reported earning nearly $27,000 from teaching at Duke University Law School and at Pennsylvania State University Dickinson School of Law. He disclosed receiving reimbursement for transportation, meals and lodging from, among other sources, the Italian American National Hall of Fame, Columbia University and Florida International University Law School.

Justices must report the receipt of gifts valued at more than $350. Alito, unlike some of his colleagues on the court, didn't report receiving any such gifts. Justice Antonin Scalia reported receiving a $1,000 shotgun from the National Wild Turkey Federation.