The investigation on the bus crash at KM3.5 of Jalan Genting Highlands on Aug 21 is 90 per cent complete.

Bukit Aman Traffic chief Datuk Abdul Aziz Yusof said the completed investigation paper would be sent to the relevant authority soon.

"We just need to weigh some important information from the agencies and experts involved on the actual cause of the accident," he told reporters during a traffic operation at KM453 of the southbound PLUS Highway near the Sungai Buloh rest area here on Friday morning.

"For example, we may have additional information on the backgrounds of the foreign passengers," he said.

In the mishap, an express bus plunged 60 metres into a ravine at Jalan Genting Highlands claiming 37 lives including its driver and injured another 16.