The president of the High Court family division, Sir Stephen Brown, who had sentenced him to 18 months for contempt of court last January, said he accepted Mr Malkin would not do it again.
Oliver, a ward of court in the sole legal care and control of his mother Elisa Pridmore, was snatched as he got off a school bus in Brittany, France, on 8 November last year. Three men held back his grandmother and two uncles as Oliver was bundled into a car. The boy was smuggled through Europe, finally turning up in Egypt.
Mr Malkin had abducted Oliver on two previous occasions, once keeping him for 19 months until he was discovered in a secret attic room at Mr Malkin's country club in Bridge, Kent.
Yesterday, the businessman made an emotional plea for his release to the judge: 'I broke the law my lord, and I apologise most sincerely to you for this, that I allowed my love for Oliver to cloud my judgement. I do ask for your forgiveness and I promise that I will never break the law again.'
He added that he had been unfairly portrayed by the media: 'I'm not a hard, shrewd businessman but a kind, gentle man. I love not only my son, but old houses, old England,' he said.
Mr Malkin's pounds 870,000 assets, which the court ordered to be sequestrated last December, included his home and business at Bridge Place Country Club, near Canterbury, and Churston Hall Hotel, near Brixham, Devon.
He told the judge: 'Prison has not only been a punishment for me, it has cost me very greatly. My private house has had to be sold, and all my personal money has had to be spent. I have borrowed from my brother Tony, and I am suffering.'
When Sir Stephen sentenced Mr Malkin in January he said that he had been guilty of a 'gross, calculated and deliberate defiance' of the court.
Yesterday he said that it was not the wish of the court that he should remain in prison. 'I now believe you recognise what you did was wrong and have fully apologised, I order your discharge from prison forthwith.'
Outside the court, Mr Malkin was in jubilant mood, hugging his girlfriend, Audrey Donnelly, who was not jailed for her part in the abduction. He said: 'It's quite wonderful being in the open air.'
When asked if he regretted abducting Oliver, he replied: 'I regret having offended the judge, but because I wasn't getting any access, I had to do it.'
Mr Malkin said that it had been difficult for the boy, who is now 13, to see him in prison. 'I've been told I can see him again at the end of next week. He loves me as I love him.'
Oliver's mother, who was ill with cancer at the time of the abduction, was not in court yesterday, and Lesley Gibson, a family friend who had acted as a go-between, said she would not be making any comment because 'enough hard things have been said on both sides and she doesn't want to enflame the situation'.
Ms Gibson said that Oliver was still traumatised and had to have private tuition to catch up on the three years of missed schooling. 'He's a very nice, sensitive caring boy,' she said.' That's the problem - he takes on board other people's feelings.' She added that he felt guilty about his father having been in prison: 'He pays the price every day.'