On October 20 a Boeing cargo plane veered off the airport's northernmost runway during landing, then hit a security patrol car and skidded into the sea.

The salvage operation was completed on Monday night and the involved runway has reopened, Hong Kong Chief Executive John Lee said Tuesday, adding that the airport was running as usual.

Two airport security staff were killed in last week's incident, with authorities saying they had been in a safe position "outside the runway area".

The city's air accident investigation authority is now conducting an investigation covering crew qualifications, flight operations and maintenance records, Lee said.

The black box flight recorders were retrieved on Friday night, and a preliminary investigation report is expected to be released within a month.

Lee said that the plane's crew, from Istanbul-headquartered ACT Airlines, has remained in Hong Kong since the crash.

Officials said earlier that both the American and Turkish civil aviation accident investigative agencies, as well as experts from Boeing, are participating in the probe.

The crash happened at the airport's newest runway, part of a HK$142 billion ($18 billion) expansion project that was completed last year.