Ninety-two year old marathon runner Fauja Singh has signed a deal with Adidas for a major advertising campaign that also features footballer David Beckham, rugby ace Jonny Wilkinson and boxer Laila Ali, daughter of Muhammad Ali.

From this week, Fauja's face will adorn billboards in cities across the United Kingdom as part of a campaign called 'Impossible is Nothing'.

In athletic terms, Fauja admits he is a "late developer".

For the first 81 years of his life he lived on the family farm in India, jogging regularly "to get from one place to the next", The Times, London, reported on Tuesday.

Before the Second World War he took part in village sports competitions, in which, he recalls, being faster than many of his neighbours.

But at 36, family commitments took over - he now has four children, 13 grandchildren and five great grandchildren - and his running came to a halt.

After his wife's death, however, when he moved to England to live with his son 11 years ago, Fauja rediscovered his old passion.

Trying to cope with homesickness, language problem and endless hours to fill, Fauja sought an activity that would fulfill him mentally and physically. He found solace in running.

Initially he took part in short-distance races of five or ten kilometers. Four years ago, after a 53-year break from the sport, he lined up for his first Flora London Marathon at the age of 89. He took six hours and 54 minutes to reach the finish, and the following year ran the same time to set a world record for 90-year-olds.

Since 2000, Singh has persistently defied perceived wisdom about age being a barrier in sport by getting faster.

Last year, aged 92, he ran almost an hour quicker than he did on his debut at the 26.2 mile distance, finishing the Toronto marathon in 5 hrs 40 min, the fastest time yet recorded by someone of his age.

This year's London Marathon next month is his immediate focus, but his ultimate goal is "to enter the Guinnes Book of Records as the oldest ever to run the distance". 

That means competing until he is at least 98.

Singh turns 93 next month and will be the oldest man ever to line up for the London Marathon.

But competition in the senior age groups is growing. Of 33,000 finishers in last year's race, 1,130 were over 60; more than 6,000 competitors take part in the biannual World Veteran Athletics championships.