India would not allow a UN investigator to join a probe of a crashed Air India jet that some safety experts had criticized for delays in analysis of crucial black box data, two senior sources familiar with the matter told Reuters.

Investigators have begun analyzing data from the black boxes recovered from the Air India Boeing 787 jet that crashed earlier this month, killing 270 people.

Investigators have downloaded flight recorder data from an Air India crash this month that killed 260 people, India's civil aviation ministry says. The London-bound Boeing 787 Dreamliner crashed moments after takeoff from India's Ahmedabad city on 12 June, killing 241 of the 242 people on board and the rest on the ground.