Three people have been arrested in connection with a fatal collision on the B4228 in the Forest of Dean.
The crash occurred at around 5.15pm on Friday (28 January) between the villages of Sling and St Braivels, and involved a blue Ford Fiesta and a red Mini.
The driver of the Mini, a woman in her 30s, died at the scene.
The other driver was taken to Southmead Hospital after being seriously injured.
Two people have been arrested on suspicion of causing death by dangerous driving. One of these has also been arrested on suspicion of perverting the course of justice.
A third person attended a police station on Saturday evening (January 29) and was also arrested on suspicion of perverting the course of justice.
They all remain in police custody.
Detectives are keen to hear from anyone who saw either the blue Ford Fiesta or a silver Volkswagen Golf driving between Coleford and Sling prior to the collision.
They are also asking for anyone with dashcam footage of either of these vehicles to come forward.
Anyone with any information can contact Gloucestershire Police online or by calling 101 and quoting incident 334 of 28 January.
Those who wish to remain anonymous can contact independent charity CrimeStoppers on 0800 555 111 or online.