Leaders of big tech companies will be asked to testify as part of an investigation into whether the companies misuse their massive market power, the head of the U.S. House Judiciary subcommittee leading the probe said on Tuesday.

The comments came a day after sources said the U.S. executive branch is gearing up for a similar probe of Amazon.com Inc., Apple Inc., Facebook Inc. and Alphabet Inc.'s Google, setting up what could be an unprecedented, wide-ranging investigation of some of the world's largest companies.

The House of Representatives Judiciary Committee opened its own investigation into competition in digital markets on Monday, with both Republicans and Democrats expressing concern about the power exercised by several of the world's most valuable companies.