Two security officials said on Saturday that the plane at Nur Khan air base arriving to carry U.S. military attache Col. Joseph Emanuel Hall out of Pakistan has returned after he failed to get clearance. He was let go by police officials in Islamabad after the accident as the law - Vienna Convention on Diplomatic Relations, 1961 - provided the diplomat immunity from criminal prosecution.
In early April, Hall allegedly ran a red light in Islamabad killing a motorcyclist and injuring a passenger.
The incident has increased political tension between the countries.
The diplomat left for Afghanistan last night on a special flight, the report said.
"We can confirm that the American diplomat who was involved in a tragic vehicle accident on April 7 in Islamabad has departed Pakistan", the spokesman said in an email to Reuters.
Pakistani media identified the diplomat as Col. Joseph Hall, who serves as the U.S. Embassy's military attaché in Pakistan.
The Islamabad High Court on May 11, on a petition filed by the deceased's father, ruled that the United States diplomat does not have absolute immunity in the country.
Diplomatic sources further confirmed that Colonel Hall was a USA diplomat who held absolute immunity as per the Vienna Convention of 1972 and the privileges Pakistan extends to diplomats.
The local police had handed over all records related to Colonel Hall to the USA officials, the report said.
Pakistani authorities made no comment about the sudden departure of the diplomat, who found himself at the centre of the latest diplomatic dispute between the two countries. It had subsequently asked the government to decide within two weeks whether or not Col Hall should be placed on the ECL.
Washington refused to withdraw the immunity of the diplomat but promised to hold him accountable under its domestic laws, Dawn quoted the sources as saying.
This is published unedited from the PTI feed.