ISLAMABAD, Pakistan — Osama bin Laden spent nine years on the run in Pakistan after the Sept. 11 attacks, during which time he moved among five safe houses and fathered four children, at least two of whom were born in a government hospital, his youngest wife has told Pakistani investigators.

The testimony of Amal Ahmad Abdul Fateh, Bin Laden’s 30-year-old wife, offers the most detailed account yet of life on the run for the Bin Laden family in the years preceding the American commando raid in May 2011 that killed the leader of Al Qaeda at the age of 54.

Her account is contained in a police report dated Jan. 19 that, as an account of that frantic period, contains manifest flaws: Ms. Fateh’s words are paraphrased by a police officer, and there is noticeably little detail about the Pakistanis who helped her husband evade his American pursuers. Nevertheless, it raises more questions about how the world’s most wanted man managed to shunt his family between cities that span the breadth of Pakistan, apparently undetected and unmolested by the otherwise formidable security services.

Bin Laden’s three widows are of great interest because they hold the answers to some of the questions that frustrated Western intelligence in the years after 2001. They are currently under house arrest in Islamabad, and their lawyer says he expects them and two adult children — Bin Laden’s daughters Maryam, 21, and Sumaya, 20 — to be charged on Monday with breaking Pakistani immigration laws, which carries a possible five-year jail sentence.