Last week former California governor Arnold Schwarzenegger, 63, and journalist Maria Shriver, 55, shocked the nation by announcing their separation after 25 years of marriage. Though the future of the powerhouse couple's union is still in question, the source of their differences has surfaced.

Earlier this year Shriver moved out of the Brentwood mansion she shared with her husband after he revealed that he had fathered a child over a decade ago with a member of their household staff. The staff member retired in January after having worked for the family for 20 years. According to Schwarzenegger, Shriver just got the news. "After leaving the governor's office I told my wife about this event, which occurred over a decade ago," he told The Los Angeles Times. "I understand and deserve the feelings of anger and disappointment among my friends and family. There are no excuses and I take full responsibility for the hurt I have caused. I have apologized to Maria, my children and my family. I am truly sorry."

Schwarzenegger requested that Shriver be left out of this, in accordance with her previous statement that the family "consider[ed] this a private matter" and would not "have further comment" about the separation. "I ask that the media respect my wife and children through this extremely difficult time," he said. "While I deserve your attention and criticism, my family does not."

The identity of the staff member and mother of Schwarzenegger's child remains concealed. It is only known that Schwarzenegger has financially provided for the child since the beginning, according to an insider. Both she and Shriver declined to comment about Schwarzenegger's statement.

During a public appearance last week, the former Mr. Universe spoke as if reconciliation between him and Shriver were still a possibility. "We both love each other very much," he said. "We are very fortunate that we have four extraordinary children, and we're taking one day at a time."