Hundreds of mourners have attended a funeral for Australian actress Jessica Falkholt, who died following a car crash that also killed her family.

The actress, a former star of TV soap Home and Away, was remembered at a church service in Sydney on Monday.

Falkholt, 29, died in hospital last week, more than three weeks after the accident on a New South Wales highway.

A funeral for her sister Annabelle, 21, father Lars, 69, and mother Vivian, 60, had been held in the same church.

"Beautiful Jess, you made us proud and you were a rising star," her uncle, Paul Ponticello, said on Monday, the Australian Broadcasting Corp reported.

"Shine bright, you will always be remembered in our hearts forever."

Australian police are still investigating the car crash, which also killed the driver of another vehicle, 50-year-old Craig Whitall.

A funeral notice published in the Sydney Morning Herald on Saturday said Falkholt would be "deeply missed" by her family and friends.

Falkholt played Hope Morrison for 16 episodes on Home and Away before leaving the show in November 2016.

Last week, Channel Seven, the soap's broadcaster, said Falkholt's "shining talent" had been respected by all of her her colleagues on the show.

Co-stars have paid tribute on social media since the accident on Boxing Day.

Falkholt also filmed a role for the US film Harmony, which is set for release this year.