On Tuesday last week, telecommunications behemoth AT&T (T  ) revealed that it had paid President Donald Trump's lawyer Michael Cohen for "insights" about the Trump administration.

Porn star Stormy Daniels' lawyer, Michael Avenatti, said AT&T had made four separate payments of $50,000 to Cohen's company, for a total of $200,000, in late 2017 and into early 2018. The allegations come in addition to Daniels also claiming drug giant Novartis (NVT  ) and a company controlled by a Russian oligarch all made payments to Cohen's shell company.

"Following these payments, reports surfaced that Mr. Trump took a dinner with the incoming CEO of Novartis before Mr. Trump's speech at the World Economic Forum in Davos, Switzerland in late January 2018," Avenatti's report said.

AT&T paid Essential Consultants LLC, a firm set up by Cohen, a total of $600,000 over 2017 for the advice. Cohen and others were hired to help navigate "a wide range of issues," including its proposed $85 billion merger with Time Warner Inc (TWX  ), CEO Randall Stephenson said in a memo seen by Reuters.

The disclosure of AT&T's relationship with Cohen has turned into a major source of chagrin for the telecommunications company as it awaits a US judge's decision, due June 12th, on whether it can go through with the purchase of Time Warner, a deal that has been denounced by Trump.

"There is no other way to say it - AT&T hiring Michael Cohen as a political consultant was a big mistake," the memo said.

In a fact sheet that accompanied the memo, AT&T said Cohen approached them about working on their behalf in the post-election transition. He was given a one-year contract at $50,000 per month, which ran from January through December 2017, that was limited to consulting and advisory services.

"To be clear, everything we did was done according to the law and entirely legitimate," Stephenson wrote in the memo. "But the fact is our past association with Cohen was a serious misjudgment."

Cohen was also hired by investment management company Columbus Nova "as a business consultant regarding potential sources of capital and potential investments in real estate and other ventures," according a statement from the company.

AT&T's head lobbyist, Bob Quinn, who oversaw the hiring of Cohen, is retiring, according to the memo. But two sources familiar with the situation said Quinn was forced to retire.

Swiss pharmaceutical giant Novartis said it made monthly payments to Cohen's company totaling $1.2 million for guidance "as to how the Trump administration might approach certain US healthcare policy matters." Novartis said it determined Cohen was "unable" to provide the desired services after a meeting in March 2017.