The Federal Trade Commission is investigating the board of directors of Apple and Google over concerns that close links between the two firms could break US antitrust laws.
US law forbids directors from sitting on the boards of competing firms, but Google's chief executive Eric Schmidt also sits on Apple's board of directors. Arthur Levinson also sits on both boards.
The FTC has already informed the two firms of its concerns, according to the New York Times. It is rare for antitrust investigators to take action over such overlapping directorships - people usually resign one or other position instead.
Although Apple and Google co-operate in some areas they are also increasingly competing, especially in the mobile market. Both firms make competing mobile platforms as well as browsers. They also compete in content - Apple's iTunes and Google's YouTube.
The investigation will also show how Obama's administration deals with its corporate friends - Schmidt advised Obama before he was elected President and still sits on the administration's technology committee.
Obama is also risking losing his support in Silicon Valley with proposed tax changes, which some fear will be a big blow to technology companies. ®