He spoke as it was revealed Miss Murrell's name will live on at a new housing development near her family home.
Miss Murrell was abducted from her house in Shrewsbury on March 21 ,1984.
Her body was found three days later in a copse in the shadow of Haughmond Hill.
Her murder remained unsolved for 21 years until builders' labourer Andrew George was convicted of her killing.
George admits being in Miss Murrell's house around the time of her murder, when he was a 16 year-old.
But he maintains that he did not kill her,and is supported in this by Miss Murrell's nephew Robert Green, who believes his aunt was killed by forces who were acting covertly on behalf of the state.
Speaking today from his home in New Zealand he said: "What I have always felt is that I will never know who killed Hilda and probably the person who did it is now dead but what is clear to me is that Andrew George did not do it.
"He was involved and he is a key witness."
Today it was revealed that streets on a new housing development on the outskirts of Shrewsbury will be named in Miss Murrell's honour.
The streets will be part of the 291-home Taylor Wimpey development in Sutton Grange, off Oteley Road, which lies just a stone's throw from Miss Murrell's Sutton Road home, where she lived all her life.
One of the streets will be called Murrell Way. Others will be called Thorn Croft, Dove Close, Gardener's Place and Old Rose Drive.
The names for the new housing development were decided after consultation with Mr Green. But council officials said the timing of the decision was coincidental and was not designed to mark the anniversary of her death.
Rachel Goodyear, who works as the street naming and numbering officer at Shropshire Council, said: "The idea to link the street names to Hilda Murrell was discussed due to the site being the former home of the Murrell family.
"Shrewsbury Town Council was in agreement that the names should be linked and that one of the streets should be named Murrell Way.
"We have discussed the potential names with Mr Green and all of the street names have been created with a subtle link to Hilda Murrell's life and her contribution to Shrewsbury and Shropshire.
"They were not intended to mark the anniversary of her death and the timing of the development is coincidental to the anniversary."
The housing development off Oteley Road is expected to create 1,300 jobs.
And it forms the first part of the Shrewsbury South Sustainable Urban Extension blueprint drawn up by Shropshire Council.
This will eventually lead to the creation of 900 new homes and 22 hectares of employment land.
For more see Friday's Shropshire Star