Technology giants including Google, IBM, Apple and Intel are being investigated by the US government over alleged breaches of antitrust laws regarding their employee hiring practices.

An article published in the Wall Street Journal stated that the vendors had been the subject of a Justice Department inquiry for the past year, with a specific focus on a supposed unwritten employment policy that the companies would not hire staff from one another.

It is reported that the investigation has now found sufficient evidence to suggest that such an agreement would impact on competition. One source familiar with the matter suggested that this restricted opportunities for employees to change jobs and receive higher pay.

"In the long run, this is going to distort and depress the incentives for people to actually develop the talents and skills that are useful in this market," Salil Mehra, a former employee of of the Justice Department’s antitrust division, now a law professor at Philadelphia’s Temple University, told the WSJ.

IBM confirmed it was co-operating with the Justice Department in relation to the antitrust investigation, while Intel refused to either confirm or deny that the probe was taking place. Both Google and Apple chose not to comment on WSJ report.