An Indian policeman who spent two months swallowing knives and had 40 of them surgically removed said Tuesday that ‘spiritual powers’ made him do it.

The father of two underwent a successful five-hour operation to remove the knives from his stomach in the northern city of Amritsar after complaining to doctors of severe abdomen pain.

‘I don't know why I did it but there was some spiritual power behind it,’ the 42-year-old told AFP from Amritsar in Punjab state, declining to be named.

‘It started in June when I swallowed the first knife and I enjoyed the feeling. It soon became a habit,’ he said.

Doctors said they initially thought he was suffering from a tumour after body scans showed a large solid mass.

But on further investigation, they discovered dozens of folding knives with metal and wooden handles and measuring up to 18 centimetres (seven inches) unfolded.

‘We immediately prepared him for surgery and removed the knives. There was bleeding as some of them were unfolded,’ Rajinder Rajan, one of the surgeons at Corporate Hospital, told AFP.

Rajan said he suspected the patient, who told doctors he passed two more knives in his stools, was suffering from depression.

Although recovering well from Friday's surgery, he would undergo a psychological assessment before being discharged from the hospital, Rajan said.

Doctors were not ruling out the possibility that he had pica disorder in which the sufferer feels compelled to consume non-edible things.

But the man said he would not do it again.

‘I consumed a knife a day for about two months. I never felt it was going to harm me but when it pained, I came to the hospital.

‘I will not repeat it. I am glad they saved my life and I want to go back to my family.’