SIR BRADLEY WIGGINS has retired from competitive cycling after one of the most remarkable careers in British sporting history.

Wiggins bows out as the owner of eight Olympic medals – a national record that includes five golds – and became the first Briton to win the Tour de France when he claimed the yellow jersey in 2012.

The 36-year-old posted a valedictory statement on his Instagram page yesterday afternoon, accompanying a picture of his collected race jerseys, medals and trophies.

In it, he said: "2016 is the end of the road for this chapter, onwards and upwards, 'feet on the ground, head in the clouds' kids from Kilburn don't win Olympic Golds and Tour de Frances! They do now."

But his departure comes at a time when cycling is once again under the microscope of anti-doping agencies and his own use of therapeutic use exemptions (TUEs) has caused significant debate.

It was revealed in September that Wiggins received three TUEs for an otherwise banned substance ahead of three Grand Tours, including the 2012 Tour.

Wiggins and Team Sky principal Sir Dave Brailsford insist triamcinolone was medically necessary for a pollen allergy which aggravates his asthma and the TUEs were approved by cycling's world governing body, the UCI.

On the same Instagram page that bears his farewell is a mocked-up picture of Wiggins as Braveheart with the legend "They can never take my package!!".

That is an apparent reference to a delivery made to Team Sky when Wiggins was competing at the 2011 Dauphine Libere, a key Tour de France warm-up race. The contents have been subject to a UK Anti-Doping investigation into alleged ''wrongdoing''.

Brailsford told a Department of Culture, Media and Sport select committee last week the package contained fluimucil, an over-the-counter decongestant available inexpensively in France.

All parties deny breaking any rules.

Shane Sutton, the former British Cycling team director and a close associate of Wiggins, appeared at the same hearing as Brailsford and provided a passionate defence of both the rider and the wider Team Sky programme.

''Knowing the kid [Wiggins] for many, many years as far as I'm concerned he never worked outside any rules," Sutton told MPs.

Reacting to Wiggins' retirement on Sky Sports News, Australian Sutton reflected on his friend's greatest triumphs.

"To win in the Tour is the dream for everybody, and a win in the Tour is probably his greatest victory, there's no two ways about that," he said.

"There's that many [successes] but the one Bradley adores the most is probably his world time trial championship [in 2014].

"That was one that was missing from the palmares [honours] and that was the one he always wanted. He got there and he'll look back on that as probably one of the big ones for him."

Wiggins, who conquered his sport on the road as well as in the velodrome, won his fifth Olympic gold in Rio this year as part of the world record-breaking pursuit team, adding to a tally that also includes a silver and two bronzes.

He competed in five successive Games from Sydney 2000 and reached a career high in 2012 when he completed an unprecedented double of a maiden Tour de France victory with Team Sky and a home Olympic triumph in the time-trial in London.

His retirement message read: "I have been lucky enough to live a dream and fulfil my childhood aspiration of making a living and a career out of the sport I fell in love with at the age of 12. I've met my idols and ridden with and alongside the best for 20 years.

"I have worked with the world's best coaches and managers who I will always be grateful to for their support. What will stick with me forever is the support and love from the public though thick and thin, all as a result of riding a pushbike for a living. 2012 blew my mind and was a gas.

"Cycling has given me everything and I couldn't have done it without the support of my wonderful wife Cath and our amazing kids."

British Cycling president Bob Howden said that Wiggins' achievements transcended sport's traditional parameters, making him a culturally significant figure.

"Eight Olympic medals and a first British win in the Tour de France are just part of the captivating story of a cycling legend, as few sports people have had the impact on life in this country as Sir Bradley Wiggins," he said.

"He retires as one of British sport's great champions, not just for the medals and the sheer diversity of races he won but also for the way in which he used his achievements to inspire so many people to become active by getting on their bikes. British Cycling has much to thank him for and we wish him success with his future plans."

Retirement this year had long been anticipated for Wiggins, but last month he won the Ghent Six Day alongside Mark Cavendish and suggested he may continue.

That race, alongside his long-time partner and in the city of his birth, will now go down as the last triumph in a long list of achievements that also includes eight World Championship wins, four Commonwealth Games silvers and, in 2015, the world Hour record.