WASHINGTON — Andrew G. McCabe, the former deputy F.B.I. director who was fired late Friday, kept contemporaneous memos about his interactions with President Trump and his conversations with the former director James B. Comey, a person close to Mr. McCabe said on Saturday.

The memos could bolster the account of Mr. Comey, whose own memos and testimony describe repeated requests by Mr. Trump to clear his name. Mr. Comey said Mr. Trump also asked him to shut down a criminal investigation into his former national security adviser, Michael T. Flynn. Both matters are under investigation by the special counsel, Robert S. Mueller III, who is considering whether Mr. Trump tried to obstruct justice.

Mr. McCabe’s memos were left at the F.B.I., which means that Mr. Mueller’s investigators have access to them as they work to corroborate Mr. Comey’s account. Mr. Trump has denied pressuring Mr. Comey to end the Flynn investigation. Mr. Comey was fired last spring, and the revelation of his conversations with Mr. Trump helped lead to the special counsel’s appointment.

Mr. McCabe is known to have had at least three meetings with the president. In one, he asked Mr. McCabe how he had voted in the presidential election. In each, he asked about Mr. McCabe’s wife, Jill, who ran a failed campaign as a Democrat for the Virginia State Senate. Mr. McCabe has identified as a lifelong Republican but did not vote in the 2016 presidential race.