Who knew? BBC in storm over bets on the new Doctor

On Saturday evening Matt Smith was named as the actor who will replace David Tennant in the popular BBC1 series. Speculation had been rife over who would be the 11th doctor, with David Morrissey and Paterson Joseph early favourites.

But more than 24 hours before the announcement, Smith's name emerged on leading online betting exchange Betfair.com - which triggered a flurry of bets on the 26-year-old.

In a matter of hours Smith dropped from 31-1 to 1-3 favourite.

Bookmakers believe someone who knew that Smith had been cast cashed in at the last minute.

Despite that the BBC has already appeared to rule out any inquiry into the possibility of a leak, with a senior official saying there was "no evidence of wrongdoing".

A betting industry insider, who asked not to be named, said: "Unlike the City of London there is no such thing as insider trading on betting exchanges. A few people have chopped it off because they knew and everyone else didn't. That's the joy of a betting exchange but also the danger. If you have people who know more than other people, some get their fingers burnt."

Odds on Smith also shortened at Paddy Power, which took £40,000 in total and saw the price fall from 33-1 to 10-1 in the past couple of days. Spokesman Darren Haines said: "Certainly to come that quickly that late in the day would, I suspect, mean that people knew."

Suspicions were raised on the TV fans' website digitalspy.co.uk. On Friday morning on the forum, which is very popular with Doctor Who fans, user Filbertthefox wrote: "Just had a look at the odds on the next Doctor on Betfair... there is a new name at second favourite - Matt Smith. Anyone got any ideas who he is or why he is suddenly this high on the list?"

A BBC TV news bulletin on Saturday morning also mentioned Smith as the possible next Doctor - and showed a clip of the actor in the BBC drama The Ruby in The Smoke.

But a BBC spokeswoman said it had "no knowledge of anyone betting on the outcome".

Sources have revealed that the BBC is unlikely to investigate as it has seen no evidence that the leak came from within the corporation.

A senior BBC source told the Standard: "It does look like somebody knew and went on the betting exchanges, but this was not necessarily someone from the BBC. It could have been an individual connected to the actor, through his associates or a friend, or even people working on the promotional material - who knows?

"If the bookmakers feel that there was some suspicious betting going on than it is up to them to investigate."

Betfair spokesman Tony Calvin commented: "Uniquely, Betfair know the identity of everyone who places a bet on the site and we are ideally positioned to monitor all of our markets to ensure they are managed correctly and fairly.

"If we have any concerns about a market we have a number of options open to us. We have Memorandum Of Understandings in place with numerous sporting bodies around the world, and will liaise with whoever is necessary as regards novelty markets such as Doctor Who, including the Gambling Commission."