Coroner calls for restrictions on the sale of helium after suicide of 'straight-A' schoolboy Grant Li,16, told his mother the gas was for an end of term party Inquest last week heard student Vivek Shah also used helium to kill himself Coroner Graham Jackson will write to Theresa May calling for law change Tragic: A coroner has called for tighter restrictions over the sale of helium after the suicide of schoolboy Grant Li (pictured) A coroner has called for tighter restrictions over the sale of helium after a straight-A student was free to buy canisters on the high street so he could kill himself. Grant Li, 16, a pupil at Manchester Grammar School, was found dead in his bedroom by his mother having told her the gas was for an end of term party. Grant had two GCSE exams left to sit, both in Mandarin, when he was found dead on June 1 last year. It was later confirmed he achieved nine A* grades and one A. He had bought helium canisters from a supermarket two months earlier. He was described by teachers as a model pupil, but had suffered from acute eczema and was under GCSE exam stress, an inquest into his death was told. Finding his cause of death was suicide, Graham Jackson, Manchester's deputy coroner, said he would write to Home Secretary Theresa May to call for greater regulations over the sale of 'party pack' helium canisters and urge changes are made to their size and control valves - a call supported by Grant's family. There are currently no age restrictions on buying helium canisters. He ruled it would never be known why the 16-year-old took his own life. The inquest heard his suicide was the fifth death involving helium in Greater Manchester in four years. Last week, an inquest heard of the death of 22-year-old Manchester Metropolitan University student Vivek Ajit Shah at a house in Rusholme, also using helium. The hard drives of both his laptop and PC were found to have been wiped, indicating that he may have carried out internet-based research, the inquest at Manchester Coroner's Court was told. Grant's mother, hotelier Yan Li, 48, described him as an intelligent and conscientious student, but revealed his eczema flared up during his revision. Bright: Grant Li was a student at the prestigious Manchester Grammar School (pictured) but had suffered exam stress in the run up to his death She said she took him to buy balloons in April ahead of a period of study leave. Mrs Li said: 'He was very hard working. He concentrated on his studies. I was pleased with his progress and he has always been a very clever boy. He said he wanted to get some helium balloons. He said that because it was the end of school term, he had to buy them and take them to school because they wanted balloons and it was his responsibility to get them. Similar: An inquest in Manchester last week found that student Vivek Shah, 22, had also used helium to kill himself The inquest heard no balloons were bought, just the cannisters. Mrs Li said she had no doubts about his intentions with regard to them and added: 'I did not notice any change in his behaviour, only on the very, very last night before his death.' The inquest heard Grant had an evening meal with his family on May 31, but was found dead in his bedroom the following afternoon. Nick Sharples, Grant's form tutor, described him as an excellent student. He said: 'A book of condolence was opened after his death. From the comments everyone talked about what a nice lad Grant was. Mr Jackson recorded a verdict of suicide. He said: 'It may be down to the problems he faced with eczema and exams, but that is pure supposition. We will never know. Grant was a young lad and the world was waiting for him. I am satisfied that he was supported by a loving and caring family. It is sad to say but who knows what he might have achieved in life? I intend to write to the Home Secretary to see if there is any way of introducing some regulation in the sale of these gas cannisters and urge regulations are introduced for control valves. I will also request that consideration is given to reducing the size or the volume of cylinders for hire or sale. Mrs Li supported the call to government. She said: 'I back what the coroner has said. I would also like to see tighter restrictions on the internet with regards to research about suicide in these circumstances.