A woman has died after she was seriously hurt while riding her bicycle at Waterfall in Sydney's south on Saturday.

Police say the 35-year-old woman was riding along McKell Avenue when she was involved in a collision with a car travelling in the opposite direction about 7.15am.

A rescue helicopter flew the woman to St George Hospital. She died from her injuries on Tuesday.

It is believed the driver stopped after the collision and inquiries into the incident are continuing.

Police had been hoping to interview the cyclist. They said their inquiries into the crash are continuing.

smh.com.au