Lt. Gen. Ricardo Sanchez (search), commander of U.S. forces in Iraq, has asked investigators to take the Abu Ghraib (search) prison abuse probe to the top of the chain of command — and that means to Sanchez himself, senior Defense officials have told Fox News. 

Sanchez has asked the Pentagon to appoint a senior investigating general who outranks him, and thus would be authorized to push the probe to the highest rungs of the command ladder, according to the officials.

Sanchez is a three-star general. The incoming investigating general would have to be a four-star general, or a three-star general senior to Sanchez in order to have full authorization to investigate any role that Sanchez and his staff may have played. Senior officials predict the appointee will be a four-star general.

By making the request, Sanchez is not admitting or implying any wrongdoing. The senior Defense officials insist that Sanchez simply wants to be certain that no level of the command chain goes uninvestigated.

With this request, the probe now purportedly goes from the bottom of the command strata — the military police either charged or alleged to have committed abuses at the Abu Ghraib prison facility — directly to Sanchez.

"Gen. Sanchez wants to make sure this is done right," one senior official said.

The highest-ranking general now engaged in just one of the abuse investigations, Maj. Gen. George Fay (search), is investigating the role played by military intelligence officials at Abu Ghraib. Fay does not outrank Sanchez.

Fay's first report was expected to be completed by the end of July, but Sanchez' request will now add to Fay's work time, as the general and his staff add Sanchez and his staff to their list of duties.

Fox News' Ian McCaleb and Bret Baier contributed to this report.