Tennis fans with tickets for the Wimbledon men's final have been warned against selling them at vastly inflated prices - as demand rockets in anticipation of an Andy Murray victory this afternoon.

Tennis fans with tickets for the Wimbledon men's final have been warned against selling them at vastly inflated prices - as demand rockets in anticipation of an Andy Murray victory this afternoon.

Last night tickets for Sunday's Centre Court spectacular were being sold online for as much as £20,000 each.

But the All England Club said it would take out an injunction against nondebenture holders selling tickets illegally.

advertisement They have askd the Metropolitan Police's economic crime unit to shut down an eBay auction, which has been advertising highly prized £200 Centre Court seats from prices starting at around £2500.

Murray, 22, is hoping to become the first British man since Fred Perry in 1936 to win the Wimbledon title.

Of course, he first must beat America's Andy Roddick in today's semi-finals.

The Dunblane-born star's success in the tournament so far has sent ticket sales soaring among those with deep enough pockets to afford the prices.

A pair of tickets for the men's final attracted a bid on auction site eBay of £2500.

Another pair, with a face value of just £200, had bids of £1260. Two tickets put on the auction site for £5000 have so far had no takers.

It is against the rules of the All England Club to sell on non-debenture tickets. Of the 15,000 seats on Centre Court, 2300 are debentures.

A Wimbledon spokesman said: "The club takes active steps to monitor and control sales including those made via shops and internet sites such as eBay.

"Sellers of non-debenture tickets will be contacted and injunctions taken out against those who do not co-operate and act contrary to the club's ticket policy."

Wimbledon officials have also been trying to crack down on fraudulent websites. One site being looked at was onlinewimbledontickets.

com, which claims to offer men's finals t i c ke t s f o r £ 210 0 , a n d presents itself as if it is an official Wimbledon site.

The spokesman added: "We have contacted the Metropolitan Police's economic crime unit. They are working with us to get the site closed down."

Meanwhile , Murray has been warned by former Wimbledon champion John McEnroe to be wary of Roddick, who holds the fastest serve in tennis at 155mph.

Roddick, who reached the final in 2004 and 2005, both times losing to Roger Federer, has hit the fastest serve so far this tournament - at 141mph.

So far he has thundered down 139 aces, second only to Ivo Karlovic.

McEnroe, now a TV tennis commentator, said: "Roddick possesses a major weapon in that serve. It's the hardest I've ever seen. At the very least he has a puncher's chance, so Murray better be ready.

Roddick's a smart guy and the pressure being off should help him."

Murray said: "Roddick is one of the best servers in the game. I'll have to return very well. He's made two finals, been number one in the world, been a grand slam champion.

It's going to be tough.

"I served well in all the matches where I've needed to, bar the Wawrinka one. If I can keep serving like that I've got a good chance against anyone. If you serve great on grass it makes a big difference to your confidence."

Murray, whose epic fourthround encounter against Stanislas Wawrinka attracted 12.6 milion viewers earlier this week, has been closing in on the title with the bookmakers.

Ladbrokes put him 1/4 to reach his maiden final and 5/2 to win it. He is also 11/8 to see off the challenge of Roddick in straight sets, but Roddick is only 11/4 to win.

Federer is 4/11 favourite for the title.

Spokesman Nick Weinberg said: "Murray has a winning record against Roddick. Punters believe their home-grown hero is unstoppable and tip him to go all the way."