Investigators found bird feathers and blood in both engines of the Jeju Air jet that crashed in South Korea last month, killing 179 people, a person familiar with the probe said on Friday. The Boeing 737-800 plane,

South Korea’s leading low-cost carrier, heavy with debt and its stock already near record lows, is now facing intense public and government scrutiny.

Investigators have confirmed the presence of bird feathers and blood in both engines of the Jeju Air jet that crashed last month in South Korea, killing 179 people, according to a source familiar with the ongoing probe.

The missing data deepens the puzzle of what caused the deadly air disaster in Muan, South Korea, late last month.

A Jeju Air jet in South Korea crashed last month due to bird strikes, leading to 179 fatalities. Investigators found bird feathers and blood in its engines. The crash occurred after overshooting the runway,

The two black boxes on the Boeing jet involved in the worst aviation disaster on South Korean soil stopped recording about four minutes before the accident, the transport ministry said on Saturday. South Korean investigators previously said the flight data and cockpit voice recorders were key to finding out the cause of last month's crash that killed 179 people.

The nation’s transport ministry reviewed structures near airport runways following the deadly crash of a Jeju Air flight late last month.