WASHINGTON — With the end in sight for Hamid Karzai’s days in office as Afghanistan’s president, members of his family are trying to protect their status, weighing how to hold on to power while secretly fighting among themselves for control of the fortune they have amassed in the last decade.

One brother, Qayum Karzai, is mulling a run for the presidency when his brother steps down in 2014. Other brothers have been battling over the crown jewel in the family empire — the largest private residential development in Afghanistan. The conflict over the project, known as Aino Mena, has provoked accusations of theft and extortion, even reports of an assassination plot.

“It’s family,” Qayum Karzai said. “They get upset, and over time they get over it. I hope they get over it.”

One Karzai brother is also said to have imprisoned a longtime Karzai aide in an effort to make him disclose the whereabouts of money and assets that relatives suspect were hidden by Ahmed Wali Karzai, another of President Karzai’s brothers and the political boss of southern Afghanistan who was assassinated last year. He was often accused of benefiting from the Afghan opium trade and an array of corrupt deals, though he denied such claims.