Nurse Kevin Cobb was jailed for life today for killing a colleague after an attempt to drug and rape her went wrong.

The 38-year-old showed no emotion as he was sentenced at the Old Bailey in London.

Cobb was given seven life sentences and may never be released as he still refuses to admit his crimes.

He was convicted of killing 31-year-old nurse Susan Annis, who lived in Haywards Heath and worked at Crawley Hospital.

He was also convicted of raping three other women he treated in the A&E department at St Peter's Hospital in Chertsey, Surrey.

Speaking at the old Bailey today Susan's parents, Audrey and David Annis, also from of Haywards Heath, said they were happy with the verdict.

Det Chief Insp Jim Dickie, of the Metropolitan Police, said: "He is where he belongs."

Cobb, who killed Susan while on a training course in London in 1996, used the rape drug midazolam to stupify his victims, leaving them with little or no memory of his actions.

But Susan suffered a fatal reaction to the drug when it triggered a heart condition she suffered from.

In sentencing Cobb, a married father, his Honour Judge Martin Stephens QC said:

"Perhaps the most tragic was the death of Susan Annis, who on all the evidence was a delightful young woman with outstanding qualities of a human being and a nurse.

"She died at your hands. After she died you continued to use the drug on your victims in order to satisfy your perverted sexual demands.

"It's difficult to envisage what could be a greater abuse of trust than you committed. They are offences of extreme gravity.

"You are a serious danger to women and I have good cause to believe you will remain a danger to the public for a period that can't reliably be estimated."

Cobb will be eligible for parole in eight years, but may never gain his freedom if he continues to deny his crimes.

Since the verdicts were brought in, another woman has come forward who believes she may also have been drugged by Cobb.

Police are investigating the case and intend to question Cobb in prison.

Det Chief Insp Dickie said: "I am pleased that justice has been done and I would like to pay tribute to the victims, particularly the Annis family, who have been through hell for the last three years."

After the case, Detective Superintendent Dave Cook, of Surrey Police, said another female patient had come forward after recognising Cobb's photograph in newspaper reports.

Police believe Cobb was responsible for attacking other female patients, but they knew nothing about it.

Mr Cook said: "If we had known about her before, Cobb would have been charged.

"Now it will be up to the Crown Prosecution Service."

Cobb was watched from the public gallery by his three surviving victims and their families.

His mother and father also looked down as he was sentenced.

Miss Annis's parents and brother were at the back of the court as Cobb was led away.

Mr Annis said: "I cannot see any way to forgive him."

Cobb was found guilty in May of manslaughter, four charges of drugging women with intent to rape and two offences of rape.