Update, July 21, 10:15 am. — After reviewing the deals, the U.S. Justice Department will file lawsuits Thursday to block two health insurance mergers — Anthem-Cigna and Aetna-Humana — Reuters reported. The megamergers, if approved, would reduce the number of major health insurers in the country to three.

The Justice Department's press release said it would announce significant antitrust news at an 11 a.m. news conference.

Original story: Federal officials are poised to try to block the proposed merger of health insurance giants Anthem and Cigna, according to two separate reports on Tuesday. The news follows an International Business Times investigative series that has raised significant questions about the economic effects of the merger on healthcare consumers and also prompted a government ethics probe in the state that had been leading the regulatory review of the deal.

Citing unnamed sources, Bloomberg and Reuters both reported that Justice Department officials are positioned to file lawsuits to halt Anthem’s multibillion-dollar acquisition of Cigna, as well as a separate merger between Aetna and Humana. The mergers would create the largest private health insurance companies in American history, and reduce the total number of major insurers to just three — a situation that groups representing physicians and consumers said could raise premiums and limit medical care for tens of millions of consumers across the country. The companies have argued that the mergers would create cost-saving efficiencies that would benefit their customers.

The Anthem-Cigna deal had been flying under the radar since it was announced in July of 2015. Since then, regulators in 12 states had quietly approved the transaction — at times without a public hearing. In June, however, the merger proposal became a flashpoint of national controversy after an IBT investigative report documented personal and familial ties between Cigna and the Connecticut Insurance Commissioner Katharine Wade, a former Cigna lobbyist whose agency is leading the national multistate review of the transaction.

The report — which explored the larger economic implications of the merger and detailed Wade’s meetings with the companies — touched off a firestorm of controversy in Connecticut, where Republican and Democratic state lawmakers demanded Wade recuse herself from the review. Connecticut Sen. Richard Blumenthal then authored a letter signed by six other senior Democratic senators asking the Obama Justice Department to block the deal.

Anthem and Cigna had been significantly increasing their campaign contributions to groups linked to Connecticut Democratic Gov. Dannel Malloy, who appointed Wade to her job. Those were just some of the campaign donations that flowed from the companies to groups that support the election campaigns of state officials whose offices have influence over the review of the deal, reported IBT. The companies also significantly increased their federal and state lobbying expenditures.

Government documents showed Malloy’s administration offering to help Cigna if it pursued a merger and spearheading legislation to empower regulators to block the release of insurance industry information, IBT reported. Other documents showed Wade using a private email address to tell ethics regulators that she had no Cigna matters before her — even as her agency was leading the review of the deal. Meanwhile, Cigna and Anthem pushed to exempt merger-related information from California’s open records laws, and regulators blocked merger-related open records requests in other states.

Reuters and Bloomberg both report that if the Justice Department does file lawsuits against the proposed merger, the companies could still fight the move in court.