Dallas-based AT&T said it was contacted by special counsel Robert Mueller's team regarding its payments to the company of President Donald Trump's personal attorney Michael Cohen.

In a statement released late Wednesday, the telecom giant said it "cooperated fully" with questions about its activities.

"When we were contacted by the Special Counsel's office regarding Michael Cohen, we cooperated fully, providing all information requested in November and December of 2017," the company said in a written statement. "A few weeks later, our consulting contract with Cohen expired at the end of the year. Since then, we have received no additional questions from the Special Counsel's office and consider the matter closed."

Mueller is investigating Russian interference in the 2016 presidential election.

AT&T is one of the companies to find itself entangled in the Mueller investigation. It is under scrutiny after the revelation late Tuesday that it was one of several companies that made payments to Essential Consultants, the shell company used by Cohen to pay hush money to adult film actress Stephanie Clifford, known as Stormy Daniels.

A list of companies that paid Cohen became public after Michael Avenatti, the attorney for Clifford, posted a link to documents on Twitter. The companies also included Columbus Nova, a company with ties to a Russian oligarch; Swiss pharmaceutical company Novartis and South Korean defense company Korea Aerospace Industries.

AT&T admitted making the payments to Cohen in a statement Tuesday. In the statement, the telecom giant said it paid the consulting firm "to provide insights into understanding the new administration." It declined to say how much it paid Cohen but said it began working with him in early 2017 and its contract ended in 2017.

AT&T may have paid Cohen's company as much as $600,000 last year, according to information first reported by Reuters. A source told Reuters the company had a yearlong contract with Cohen.

On Wednesday, AT&T sent an email to employees in response to news reports. "We want you to know the facts," the company wrote.

In the message to employees, AT&T said Cohen was one of several consultants the company hired to gain a better understanding of the new administration. It said it sought advice about how Trump and his team "might approach a wide range of policy issues important to the company, including regulatory reform at the FCC, corporate tax reform and antitrust enforcement."

AT&T said its contract with Cohen ended in December 2017, and it did not learn about "the controversy surrounding Cohen" until media reports in January 2018.

AT&T did not say what the special counsel asked about its payments to Cohen or its dealings with him when contacted in late 2017.

AT&T has a major merger that is pending in a Washington courthouse. The telecom company wants to acquire media and entertainment company Time Warner in a deal that's valued at nearly $109 billion, including debt. The Justice Department sued to block the merger in November 2017, saying it would hurt competition and drive up prices for consumers.

The antitrust trial ended last month, and a ruling is expected by June 12.

Novartis, the pharmaceutical company that made payments to Cohen's company, also said Wednesday that it had been contacted by Mueller's office. In a statement, the company said it "cooperated fully" and "provided all the information requested" when asked in November 2017 about the company's contract with Essential Consultants.

In its statement, Novartis said it sought advice on health care policy, but Cohen could not deliver what he promised. It paid $1.2 million to Cohen over the course of a year.

"Novartis considers this matter closed as to itself and is not aware of any outstanding questions regarding the agreement," it said in the statement.

Korea Aerospace Industries said it paid Cohen $150,000 for consulting services. A spokesman for the company told Reuters it had not been contacted by Mueller's team.

On Capitol Hill, the questions may just be beginning for AT&T.

On Wednesday, two lawmakers — Democratic Sens. Richard Blumenthal of Connecticut and Ed Markey of Massachusetts — called for an investigation of AT&T's payments. Two others, Sen. Amy Klobuchar of (D-Minn.) and Rep. David Cicilline of (D-Rhode Island), wrote a letter to antitrust chief Makan Delrahim, asking if the Justice Department knew of AT&T's payments to Cohen or any attempts to influence the merger's outcome.