Authorities in India sent the wrong remains to some British families whose loved ones were killed in a plane crash last month, their lawyer has claimed, as relatives reckoned with the human cost of the world’s deadliest aviation accident in a decade.

The mistakes were found after DNA testing by a coroner in London. The Indian government said bodies of the Flight 171 victims “were handled with utmost professionalism.”

Preliminary report reveals Air India crash was triggered by sudden fuel cut-off after take-off, killing 260, cockpit confusion and faulty switches noted.