Washington, Dec 17 (IANS): A lawyer for US President Donald Trump's transition team has accused Special Counsel Robert Mueller of unlawfully obtaining documents including thousands of emails without their knowledge, for its ongoing probe into alleged Russian meddling in the 2016 presidential election.

Kory Langhofer, counsel to Trump for America (TFA), said in a letter on Saturday to several congressional panels that Mueller's team obtained these emails from the General Services Administration (GSA), the government agency that hosted the transition email system, reports Xinhua news agency.

In the seven-page letter, he accused Mueller's team of "unlawfully producing TFA's private materials, including privileged communications, to the Special Counsel's Office".

The lawyer urged the Senate Homeland Security and Governmental Affairs Committee and the House Oversight and Government Reform Committee "to protect future presidential transitions from having their private records misappropriated by government agencies, particularly in the context of sensitive investigations intersecting with political motives".

Mueller's probe into the alleged Russia meddling entered a new phase earlier this month when former National Security Adviser Michael Flynn pleaded guilty of lying to the FBI about his contacts with Russia.