The investigation into the death of Melanie Hall took a dramatic turn last night with the arrest of a 39-year-old man on suspicion of her murder and disappearance.

Avon and Somerset Police said the man, from Wiltshire, was arrested at 4pm after he went voluntarily to an unnamed police station in the county. He was in custody and being questioned.

Melanie, who lived with her parents Pat and Steve in the village of Bradford Leigh, near Bradford on Avon, was last seen on the dance floor of Cadillacs nightclub in Walcot Street, Bath, in the early hours of June 9, 1996 – she was aged 25.

Her disappearance sparked one of the biggest police investigations in the West's history. It appeared – until her remains were discovered bound in rope and dumped in a black bin bag at the side of the M5 at Thornbury last October – that the case would be forever unsolved.

But that discovery gave the murder inquiry new impetus.

When she was found her body had been stripped of all clothing and jewellery except, bizarrely, a treasured ring given to her by her grandmother, which was left on her finger and proved, 13 years later, to be the key to identifying Melanie.

On July 1, a 38-year-old Bath man was arrested on suspicion of her murder and disappearance, and was later released on bail.

Detective Chief Inspector Gareth Bevan, of the murder inquiry team, described the arrest as an important step but stressed that the investigation was still going on.

He said: "Since Melanie's body was found last October, the investigation team has continued to work tirelessly, following up new information we have received and revisiting the previous investigations that followed Melanie's disappearance from Walcot Street in June 1996.

"An additional 250 statements have been taken, and 1,200 new tasks and investigative actions have been completed. Today's arrest was one such action."

He said Melanie's parents were always kept informed and were aware that police had made an arrest.

He said: "The murder inquiry team remains active, positive and determined to find Melanie's killer or killers and bring them to justice.

"I repeat our appeal for anyone with information to contact the murder incident room on 0117 9455811 or Crimestoppers on 0800 555111."