WASHINGTON (REUTERS) - Apple Inc on Friday (June 12) said it has tightened some of its rules for responding to legal requests after the US Justice Department during Donald Trump's presidency subpoenaed it for information on Democratic lawmakers.

Apple said it recently instituted a limit of 25 identifiers such as e-mail addresses or phone numbers per legal request.

The Cupertino, California-based company said it received a subpoena from the Justice Department in February 2018 for information on 109 identifiers made up of 73 phone numbers and 36 e-mail addresses, but that it did not release content such as e-mails and pictures to prosecutors.

The New York Times on Thursday reported that federal prosecutors subpoenaed Apple and other companies as part of an investigation searching for the sources behind news media reports about contacts between Trump's associates and Russia.

The investigation targeted at least two Democrats on the House of Representatives Intelligence Committee, aides and family members, including one minor, the Times reported.

Apple said that it had no way to tell what the nature of the investigation was and released only basic "account subscriber information" such as names, addresses, e-mail addresses and telephone numbers, as well as connection logs and IP addresses.

Apple said that it did not provide data showing to whom or when messages of any kind were sent.

Justice Department Inspector General Michael Horowitz said on Friday he will investigate the department's efforts under Mr Trump to seize the communications data of lawmakers and members of the news media.