Police have released CCTV of the last sighting of a missing 17-year-old with an unknown man in Oxford city centre.

Officers are “increasingly concerned” about the whereabouts of Iris who has been missing from Aylesbury since May 3.

They would like to speak to the man who was seen with her in Oxford city centre on that day.

Iris is around 5ft 8ins tall and of slim build. She may be wearing a black and red jacket, black jeans, black trainers and a black cap, as seen on CCTV.

Oxford Mail: Iris, aged 17, has been missing since Friday (3/5)

She has known links to Swindon, Hemel Hempstead and Watford, as well as Wales, Liverpool and Manchester.

Iris may also be using the railway network for transport.

Superintendent Matthew Bullivant said: “We are extremely concerned for Iris’ welfare as she has been missing for more than a week.

“Iris was seen with a man in Oxford city centre on May 3 so we are keen to speak to him as he may have vital information about her whereabouts.

“I would like to emphasise, he is not a suspect of any offence, he is simply the last known person to speak to Iris so we need to speak to him as soon as possible.

“Iris is believed to have boarded a train at Oxford railway station heading for Birmingham so please get in touch if you were possibly on this train and saw her.

“Iris, if you see this, please get in touch with police or visit a police station so we can confirm you are safe. You are not in any trouble, we and your family are just concerned about you.

“Anyone who sees Iris should call 999 immediately. Or anyone with information that can help us find her, or the man pictured, or the man himself, should report it on our website, quoting reference number 43240206731.”

Iris’ mother said: “Iris you're not in trouble. We want you home. We love you and we miss you.”