Saudi Crown Prince and Defence Minister Sultan bin Abdul Aziz, absent from the country for more than one year for medical treatment, will return within several weeks, his son said Sunday. 'He has completed the treatment period and stopped taking medication about two months ago,' his son Prince Khaled bin Sultan said, according to a report on the official SPA news service. 'He is now in excellent health and will arrive back home during the next few weeks, God willing,' said Khaled, the deputy minister of defence, at King Khalid Air Base in southern Saudi Arabia. Prince Sultan, first in line for the throne now held by his half brother King Abdullah, and for 47 years the powerful defence and aviation minister, left for the United States for medical tests on November 23, 2008. Sultan, 81, underwent at least two treatments in New York, convalescing in his palace in Agadir, Morocco after both. Several times since May officials have raised expectations of his imminent return, but he remained in Agadir. His illness has never been officially reported, but it is widely believed he has been taking treatment for colon cancer. Also holding the title of deputy prime minister, his illness left an administrative vacuum, making it difficult for King Abdullah, the prime minister, to be absent. On March 27 Sultan's younger full brother Interior Minister Prince Nayef bin Abdul Aziz was named second deputy premier, allowing Nayef to preside over cabinet meetings and other official duties when Abdullah was absent. Some political analysts believed the move also indicated Nayef would become crown prince if something happened to Sultan. Sultan and Nayef are part of the 'Sudairy Seven', a powerful group of sons of King Abdul Aziz al-Saud, the founder of modern Saudi Arabia. The group included King Fahd, upon whose death in 2005 Abdullah ascended the throne and Sultan became crown prince. 