A police chief hunting a dangerous sex attacker who beat and left a woman for dead on Ilkley Moor a year ago today vowed to get his man.

Detectives, who have already eliminated 2,500 potential suspects from the investigation, are stepping up their inquiries on the eve of the first anniversary of the vicious attack.

The 52-year-old victim was walking her dogs near the Panorama Reservoir at 4pm last June 26 when she was knocked to the ground by her knife-wielding attacker, who tried to strangle her.

During a desperate struggle the woman grabbed hold of the knife and jabbed him with it before being overpowered. The brave victim, who suffered severe facial injuries, lost consciousness and when she came round the man had fled.

Forensic evidence has directly linked the attacker to the rapist who brutally assaulted a teenager at knifepoint nine years earlier in Leeds.

The 16-year-old girl was raped in front of her 11-year-old brother as they collected frogspawn at the Primrose Valley beauty spot in July 1997.

On Monday police will be setting up a static caravan in the central car park at Ilkley to show footage of an appeal they ran on Crimewatch along with local news coverage and an E-fit of the man's face. There will be a matching appeal in Leeds.

Detective Superintendent Paul Kennedy, who is leading the investigation, said: "We are not going to stop until we get this man. We are never going to give up because this man is still a danger to women. Once we find out who he is we can make sure he does not hurt anyone again."

Police believe the attacker either lived, worked or socialised in the two locations when he struck.

The Ilkley suspect was white, aged about 40, and 5ft 9ins tall. He was toned and athletic but not muscular, had an unusually craggy and weather-beaten skin and a distinctive round mark, possibly a mole or blemish, a quarter of a centimetre in diameter, just above his lip.

Anyone with information can call Crimestoppers on 0800 555 111 or text a message to 07786 200806 with the word Ilkley'.