Police are trying to trace a woman who called them about a crash in which a motorcyclist was killed.

The woman could be a key witness and police are anxious to speak to her again.

Christopher Clark, 25, of Church Coombes in Tillington, near Petworth, died from his injuries following the collision shortly after 9pm on Monday night on the A272 at Stedham, near Midhurst.

It is believed he came off his Triumph motorcycle before he was struck by another vehicle that left the scene without stopping.

The woman phoned police who have since been unable to speak to her.

Officers have now released a tape of some of the conversation between her and the operator in a bid to trace her.

Inspector Mark Trimmer said: "It is imperative that we trace this woman as she may be a key witness to what happened.

"Christopher's family, understandably, are distraught by this tragedy and we want to find out exactly what happened.

"We're also appealing to any other witnesses who have not yet come forward to give us a ring."

In the tape, the woman said: "Hi, I wonder if somebody ..."

There is then a brief dialogue between her and the police operator.

Woman: "Yeah, the A272 Midhurst to Petersfield Road."

Operator: "What time was this?"

Woman: "About nine o'clock this evening just before ..."

She is then heard to say: "No, I didn't, no, it's just that I drove past and I saw a few police cars."

Finally, the words "tootled off" are used.

Any information to 0845 6070999.