A married couple who were killed in an alleged hit-and-run as they rode a tandem were hoping to start a family and were due to start IVF treatment, friends have said.

Ross and Clare Simons - described by friends as "two peas in a pod" - had just been given the go-ahead to start fertility treatment.

They celebrated the happy news on Saturday night with friends at a meal. Less than 24 hours later, Mr Simons, 34, and his 30-year-old wife died when their bicycle was in collision with a Citroen Picasso car in Hanham, near Bristol.

Police said the car struck another vehicle before colliding with Mr and Mrs Simons's bicycle.

The couple, who had been married for about 18 months and had been together for several years, died at the scene of the crash on Lower Hanham Road.

A 38-year-old man, who is alleged to have fled after the collision, handed himself in to police hours later. He remains in police custody having been arrested on suspicion of causing death by dangerous driving. A 35-year-old woman has also been arrested on suspicion of dangerous driving.

Avon and Somerset Police confirmed the matter has been referred to the Independent Police Complaints Commission because an officer had attempted to stop a speeding Citroen Picasso before the collision.

Family friend Diane Pullin, from Kingswood, Bristol, said: "They are a lovely family, so kind and so helpful. They'd just had news that they were able to have fertility treatment... everything to live for. They were trying for children and they had just been told they could have fertility treatment. It's just terrible and it shouldn't have happened."

The families of Mr and Mrs Simons released a short statement paying tribute to the couple.

"Both of our families are completely devastated by the tragic events that took Ross and Clare from us," they said in the statement released by police. "A very special couple have been taken from us and we have no words to describe our loss. We would all appreciate it if our privacy was respected at this difficult time in order for us to grieve as a family."