Michael Jackson's doctor Conrad Murray caused the star's death through negligence and greed, depriving his children of their father and the world of a 'genius,' a prosecutor said yesterday.

Presenting what he called an 'overwhelming case' against Dr Murray at the climax of his manslaughter trial, Deputy District Attorney David Walgren said the medic invented elaborate lies to cover his tracks over the 2009 death.

'Conrad Murray in multiple instances deceived, lied, obscured, but more importantly Conrad Murray acted with criminal negligence,' he told the seven-man, five-woman jury that will shortly decide the doctor's fate. Dr Murray above all wanted to protect his $150,000 a month salary for looking after Jackson, Mr Walgren said, describing how the doctor agreed to treat the star's insomnia with the anesthetic propofol against all medical advice.

'Conrad Murray looked out for himself and himself alone. He wanted this employment... so he had to say yes' when Jackson asked him for propofol -the drug that killed the star -to help him sleep.

Presenting his closing argument to the six-week trial, Mr Walgren highlighted the impact of Jackson's death on his three children.

'The evidence in this case is overwhelming... that Conrad Murray acted with criminal negligence, that Conrad Murray caused the death of Michael Jackson, that Conrad Murray left Prince, Paris and Blanket without a father.

'For them this case doesn't end today or tomorrow or the next day, for Michael's children this case will go on forever, because they do not have a father,' he said. Dr Murray, 58, is charged with involuntary manslaughter for causing Jackson's death by giving him an overdose of the surgical anesthetic propofol, combined with other sedatives, on June 25, 2009 to help the King of Pop sleep.

The defence has argued that Jackson was a desperate drug addict who caused his own death by taking more medicines while Dr Murray was out of the room at the star's rented mansion in Los Angeles.

But Mr Walgren said the doctor could not escape the responsibility for the drugs that killed Jackson. 'A doctor has a... solemn obligation to first do no harm... Conrad Murray violated that sacred trust each and every day,' he said.