Olympics has brought new audience to theatres, says composer who predicted London 2012 would be a disaster for West End

Sales for shows in theatres owned by Andrew Lloyd Webber have risen by 25% during the Olympics, leading the composer to admit that his prediction of "a bloodbath of a summer" was off the mark.

According to the Daily Telegraph, box office takings for shows including Matilda the Musical, The Phantom of the Opera, War Horse and Shrek – all being performed in theatres owned by Lloyd Webber's Really Useful Group – spiked by around £250,000 last week. Even The Wizard of Oz at the Palladium, which Lloyd Webber had considered closing during the Olympic fortnight, has risen by £100,000 each week.

But the positive figures come despite a dip in the number of tourists heading into West End shows, suggesting that domestic theatregoers are capitalising on last-minute deals and increased availability.

Lloyd Webber said: "I'm the one who said it would be all doom and gloom, but I have been proved wrong and I couldn't be more delighted about that."

He added: "I thought it was going to be terrible because there would be no foreign visitors whatsoever, and it is true that we're not seeing the foreigners we normally get at this time of year.

"But what is happening is that a lot of families from all over the country are coming to see things such as the equestrian events or the volleyball … and saying, 'What else can we go and see?' So suddenly we see this huge upturn, and what's interesting is that they are clearly all Brits."

Last December, Lloyd Webber told Radio 4's Today: "Nobody's going to go to the theatre at all." He also predicted the "ordinary West End tourist audience" would fall dramatically, suggesting that three major musicals would close for the duration.

The Stage reported last week that there had been a "noticeable drop" in advance box office sales during the Olympic period, with Julian Bird, chief executive of the Society of London Theatre, telling the industry paper that "it's all to play for".

However, not everyone is as upbeat as Lloyd Webber. On 30 July, producer Nica Burns told the Financial Times that she was expecting a 30% drop across the summer compared to the previous year. "We're bleeding, darling," she said. "For my six theatres, last week was the worst this year."

Her comments caused the culture secretary, Jeremy Hunt, to dismiss reports of a struggling West End as "absolute nonsense", though Bird said at the time that the period immediately before the Games "had been a very quiet week".