Tony Podesta, founder of the Podesta Group lobbying firm, is leaving the company after becoming a subject in Special Counsel Robert Mueller's investigation, Politico reports.

NBC News reported last week that Podesta's company had worked on a public relations campaign that former Trump campaign chairman Paul Manafort had organized to improve Ukraine's image in the West.

An indictment against Manafort and an aide on money laundering and tax evasion charges was unsealed Monday.

Podesta, a Democratic lobbyist whose brother John was Hillary Clinton's presidential campaign chairman, announced his decision to step down during a company meeting on Monday morning, Politico reported. He will give full operational and financial controls to CEO Kimberley Fritts, according to Politico.

Fritts and a senior group of people will launch a new firm within the coming days, Politico reported, noting that sources said the transition has been in the works for the past several months.

Neither Tony Podesta nor The Podesta Group immediately responded to CNBC's requests for comment.

Read Politico's full report here.