The US House Judiciary Committee has subpoenaed the Department of Homeland Security (DHS) chief over questions about whether officials were offered pardons by President Donald Trump.

The committee issued the subpoenas on Wednesday, having approved them in July. House Judiciary Chairman Jerrold Nadler said the subpoenas were part of the panel’s investigation into whether to pursue articles of impeachment against Trump.

“The dangling of pardons by the president to encourage government officials to violate federal law would constitute another reported example of the president’s disregard for the rule of law,” Nadler said in a statement.

The questions centre on acting Homeland Security Secretary Kevin McAleenan. Shortly after McAleenan took over, Trump told him he would pardon him if he were to find himself in trouble for blocking people seeking asylum, people familiar with the conversation told The Associated Press. The people spoke on condition of anonymity.

McAleenan has said he was not asked, directed or pressured to do anything illegal, but has also said his conversations with the president are privileged information.

The committee said the subpoena required McAleenan to appear before the panel at 10am (14:00 GMT) on September 17 to provide a number of documents, notes and communications including those related to March 21 and April 5 meetings between Trump and DHS officials, according to a copy of the subpoena released by the panel.

DHS did not respond to a request for comment on Wednesday evening.

The panel, which is actively considering whether to recommend impeachment proceedings against Trump, is also investigating alleged hush money payments made just before the 2016 presidential election to two women who claim to have had affairs with Trump and alleged violations of constitutional bans against officials receiving payments from foreign and domestic governments.