(CNN) Federal prosecutors have requested information about former top GOP fundraiser Elliott Broidy's contacts with foreign leaders and businesses while working for President Donald Trump's inauguration, according to sources familiar with the investigation.

The request comes as part of a probe into whether Broidy, a Los Angeles private investor, sought to sell his influence with the Trump administration

The US attorney's office for the Eastern District of New York in April subpoenaed the President's Inaugural Committee seeking documents and records relating to Broidy, five companies associated with him and foreign politicians -- including the presidents of Angola and the Republic of Congo and two Romanian politicians, the sources said.

The grand jury subpoena also requests information about George Nader, a key witness in special counsel Robert Mueller's investigation who was arrested last month on child pornography charges. Other names listed on the subpoena include a Nigerian businessman, GOP fundraiser Lisa Korbatov and Nicky Lum Davis, a Hollywood producer and fundraiser, according to the sources.

All of the individuals cited in the subpoena have ties to Broidy. The inaugural committee complied with the subpoena soon after it received it, according to the sources.

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