Frequent Google critic Consumer Watchdog wrote to the White House Counsel on Friday arguing that President Obama and other administration officials must distance themselves from Google during pending federal investigations of the search giant.

"It’s unheard of for the President to publicly embrace a corporate executive whose company is under criminal investigation by the U.S. Justice Department," said Consumer Watchdog President Jamie Court and Privacy Project Director John Simpson.

"Nonetheless, the Obama Administration continues to have close relationships with top executives of Google Inc. while the company is the target of serious federal investigations for possible wrongdoing."

Google is currently under review by the government for allegedly selling ads to illegal online pharmacies; the Justice Department is also evaluating Google's proposed acquisition of Admeld for antitrust concerns. Most notably, the Federal Trade Commission is reportedly poised to bring a broader antitrust probe of the firm's core search business.

The pair note Google executive chairman Eric Schmidt and a company vice president were both guests at a State Dinner honoring German Chancellor Angela Merkel, and argue the invitations undercut federal investigators by indicating White House support for the firm.

"It has long been a tradition to invite some business leaders to attend these White House functions. However, executives of companies under federal criminal investigation should not be invited while a major case is pending," the two wrote, referring to the drug-ad investigation.

"Clearly, entertaining Google executives at the White House while a case of this magnitude is pending poses an inappropriate conflict of interest."

The letter acknowledges Obama "has had a warm relationship with Eric Schmidt," noting his role on Obama's transition team and as an adviser on science and technology, but argues he must still distance himself from Schmidt and Google until the allegations are resolved.