The family of a Holocaust survivor who was murdered in London 27 years after she was liberated from a concentration camp in Prague have made a new appeal to bring her killer to justice.

Emmy Werner, 68, was found by a chambermaid at the Queens Hotel in Bayswater, London, in September 1972.

Detectives believe she was attacked in her room in the early hours of the morning and the most likely motive was theft.

A 16-year-old boy was arrested within a few weeks of the murder and charged, but he was acquitted at the Old Bailey in February 1973.

Now, on the 45th anniversary of her death, the Metropolitan Police said it would take a fresh look at the murder in the hope the passage of time may provide some clues and encourage people to come forward.

A reward of up to £20,000 is being offered for information leading to the arrest and prosecution of her killer.

Carolyn Franks, Mrs Werner's granddaughter, said: “My grandmother was a vulnerable woman and no one should have to die like she did, especially after the trauma she had already endured.

"The effect on her close family continues to be a source of great sadness to us and we feel whoever killed her should be held to account.”

Mrs Werner, her dentist husband Albert and their daughter Hedy lived a comfortable life in Brno, Czechoslovakia, until the German occupation in 1939.

In 1942, she was transported with Albert and Hedy to the Theresienstadt concentration camp near Prague.

In October 1944, Mr Werner was taken to Auschwitz and then, as the Allied troops advanced, on to Kaufering concentration camp where he was killed in February 1945.

Mrs Werner and her daughter, then aged 17, were liberated in May 1945 and moved to London in September 1946.

They lived with relatives before settling in the Finchley area.

Mrs Werner suffered from mental health problems for years due to her war-time experiences but eventually made progress through treatment.

She moved to a residential care home in Finchley but visited her sister in central London regularly, staying at the Queens Hotel.

On the evening of Saturday, September 16, she had been to the Vaudeville Theatre on the Strand with two friends to see Move Over Mrs Markham, before settling for the night at her hotel.

Officers now hope to trace people who used to work at or visit the hotel in the 1970s, who were mostly of different nationalities, including German holidaymakers and Swedish staff.

Detective Inspector Susan Stansfield said: “Although many years have now passed since Emmy's death, it remains particularly difficult for her family that she survived the horrors of the Holocaust yet died in such brutal circumstances.

“Emmy was 68 years old and was physically and mentally vulnerable due to her past. The hotel served a mixture of guests and employed a number of staff who were spoken to by police at the time. However, with the passage of time, it is possible that the events of that night have since been discussed and there is information that could be really useful to our inquiry.

“Or maybe someone who was scared to speak to officers at the time might now feel able to come forward. Did you stay or work at the hotel or in the area of Inverness Terrace, west London, in the early 1970s?

“Has anyone told you anything in confidence that you feel you should now disclose to police? We would also be interested in speaking to the friends - one from the hotel and an Italian woman - who Emmy went to the theatre with that night, in case they have any useful information.”

Anyone with information should contact the Met on 020 7230 4294 or contact Crimestoppers on 0800 555 111.