A leading British academic has warned the world's Helium supply is on course to run out in just 10 years.

Professor David Cole-Hamilton last night urged people not to let off birthday party balloons into the atmosphere as the inert gas was needed for MRI scans and deep sea diving.

There is no chemical way of manufacturing helium; the supplies on Earth come from the very slow radioactive alpha decay that occurs in rocks.

Prof Cole-Hamilton, Emeritus Professor of Chemistry at the University of St Andrews in Scotland, added supplies of Indium, which is used to create smartphone and TV screens were due to run out in 20 years.

He said: "By having Helium balloons at your birthday party you may prevent people from having an MRI scan.

"We are recycling it from the MRI scans and most of it from the deep sea diving but we are not recycling from the balloons.

"In both of those applications it's recycled, however Helium is very very light, if it gets into the atmosphere it can escape.

"If we recycle I think we would be fine but if we gradually put balloons up in the atmosphere then the timescale will be shorter.

"The timescale is shorter than Indium - it is ten years."

The Professor explained the world had about six years of Helium supply from a mine in Tanzania with the rest coming from the US.

Smartphones could become unaffordable without better recycling of the chemicals in them, he added.

Prof Cole-Hamilton said Indium, which is currently obtained from zinc ore mining, was the first of some 30 elements used to make smartphones that will run out at current rates of recycling.

He said: "That ore will run out in about 20 years in the rate we are using it.

"We will be able to [build mobile phones] but it will become much more expensive.

"We would have to pay more for it and probably people at the lower end of the economic activity spectrum would find each much more difficult but may they would keep their phones for longer.

"But I think that won't happen because scientists are waking up to the fact that this is a problem."

Describing what he believes needs to happen to avoid elements running out, he said: "We have to first of all reduce the number of mobile phones. We exchange one million mobile phones in the UK every month.

"Secondly, we should be able to replace the battery, then we have to recycle all the elements that are in it and we have to look for replacements which are more abundant."

Asked who was responsible, he said: "The consumer and of course, the manufacturers because they want to sell more phones, they want you to change your mobile more often.

"We have to have a proper process for recycling materials."