The parents of a 21-year-old who died of an undetected heart defect hope screening paid for by donations in his memory will prevent more deaths.

Ollie Marsden suddenly collapsed and died during rugby training in Totnes, South Devon, in 2008. Now, the £30,000 raised by friends, family and supporters will pay for hundreds of young people to be screened, in the hope that another tragedy can be averted.

Ollie's father, Kevin Marsden, urged young people to sign up. He said: "Ollie's death was just devastating. Words can't describe it. One minute, life's as normal as can be, and then you get the news and everything changes forever."

But Mr Marsden said he and his wife Linda feel comparatively lucky because of the support they have received. They now want to give something back through the screening events.

"Our way of dealing with Ollie's death was to go out and raise money," he said. "We have been able to do something positive. We firmly believe that screening is the answer."

Each week, at least 12 apparently fit and healthy young people die of a heart defect they did not know they had. A simple and painless electrocardiogram (ECG) test could have saved their lives. This will be available to anyone aged between 14 and 35 at Totnes Leatside Surgery on March 17.

Mr Marsden said: "Young people have got everything to gain and nothing to lose. Being ignorant about it isn't an option. Just have the screening. If only we'd have known, we would have made sure Ollie was screened."

The test costs around £35, but it will be free, funded by donations made in Ollie's name and carried out by the charity Cardiac Risk in the Young (CRY).

A further screening event will take place at Plymouth University, where Ollie was training to be a teacher, and it is hoped more will be held in the future.

Dr Steven Cox, CRY's director of screening, said: "The death of a young person is heartbreaking and devastating for any family."

He believes screening should be extended to all young people, and said those who play sport are particularly at risk.

"It is essential that anyone with a condition knows about it. If they continue to participate in sport or take particular medication, for example, they could be putting their lives at risk," he said. "They may not show any symptoms or warning signs."

To book a screening appointment or for more information, go to www.c-r-y.org.uk/ecg.htm.