The three people killed in the logging truck crash on State Highway 1, near Tokoroa, on Tuesday have been identified.

Warren Lee, 53, his 52-year-old wife Aesoon Lee and their 20-year-old daughter Julia Lee were killed when their car crossed the centreline and crashed with a truck travelling south on SH1.

An 18-year-old man remains in critical but stable condition in Waikato Hospital.

Warren and Aesoon Lee were American citizens living in Hong Kong.

Their daughter Julia Lee had been living in Massachusetts, but was due to start university in Auckland. Her family had come over to settle her in before heading back home.

Her 18-year-old brother, also an American citizen living in Hong Kong, remains in a critical but stable condition in Waikato Hospital.

Police say Julia was driving the car when it crashed.

'Her brother was a front seat passenger and her parents were in the rear of the vehicle,” say police.

The investigation into the cause of the crash is continuing.