CARACAS, Venezuela — The administration of President Nicolás Maduro called it a necessary move to ferret out “putrid” corruption and end impunity. Outside the government, however, many observers saw it as yet another strong-arm move by Mr. Maduro to consolidate power.

Whatever the motivation, the arrests this week of six senior executives at Citgo, the United States refining subsidiary of Venezuela’s state-owned oil company, have purged the American company’s leadership and stunned the energy sector.

The move, announced on Tuesday by Venezuela’s attorney general, was the latest in an inquiry that has led to the arrests in recent months of about 50 people associated with the vital national oil industry. The purge has come as the state-owned company, Petróleos de Venezuela, or Pdvsa, teeters on the brink of default on billions of dollars in bond debt amid the nation’s worsening economic crisis.

Attorney General Tarek William Saab said the six Citgo executives, including the acting president, faced charges of embezzlement and other crimes in connection with a refinancing deal worth as much as $4 billion that had not been authorized by the appropriate authorities in the Maduro administration. He said the officials had offered the subsidiary as a guarantee, putting it “at risk.”