Imran Khan is crestfallen. Throughout the morning, his BlackBerry has been in a state of perpetual agitation. He is intending to spend the day delivering relief goods for those devastated by the worst floods in Pakistan's history, gathered by his new charitable fund, but another story has overtaken the public's interest in that. Instead, the world's media wants to hear Pakistan's greatest living cricketer's reaction to the scandal that has suddenly involved the national game.
"It just took everyone by surprise because it was so embarrassing," says Mr Khan. We are heading down the motorway into the north-west, an area that was first ravaged by militancy and now devastated by the floods, and a destination that puts the apparent greed of his successors in the national team that much more difficult to take.
"There's the war on terror, this flood devastation, all of this just made it that much more demoralising," he goes on. "We still call them allegations, until we hear the other side. But, potentially, this is the biggest setback to Pakistani cricket ever."
Over 18 years since he led Pakistan's only World Cup triumph, Khan remains its only genuine global celebrity. As leader of the Justice Movement, he sits in the political wilderness, having lost the party's sole parliamentary seat by boycotting the last elections. But his philanthropy has seen him establish both Pakistan's only free cancer hospital – for which he raises $20m a year – and a heavily subsidised university in his ancestral town.
"I'm the biggest fundraiser in this country," Mr Khan says, returning waves to admirers in a passing car. "I realised that we had to do something. There's no question of us sitting back and watching this tragedy unfold."
Teaming up with Geo, Pakistan's most-watched television channel, Mr Khan has set up his own flood relief fund. The government failed to rise to the occasion, he says. "We launched the appeal eight days ago," he says, "and the response has been phenomenal. We've already raised five million dollars. The money's coming in all the time." It's well short of what the British people have raised, but still the largest sum yet collected privately in Pakistan.
The plan today is to dispatch 150 trucks, laden with wheat, rice and other goods, to various towns in the north-west. One problem: the trucks are marooned in different places, with only six accompanying Khan.
Meanwhile, the texts and calls are unrelenting. Briefly trading his black Ray-Bans for an unfashionable pair of reading glasses, he reads out a message saying that an official refused to shake the hand of Muhammad Amir, one of the accused bowlers. The spectacles are then lifted to reveal his pained disappointment.
The controversy recalls a moment in 1989, when he was warned of a plot to corrupt his team. "I was called in the middle of the night," he says. "It was the final of the Australasia Cup against Australia in Sharjah. I was told that four of our main players had either been bought or would throw the match."
The next morning, Mr Khan summoned his team. "I told them, 'Look, I know all of you and I know cricket. If I see any of you underperforming, I will not just have you banned, I will ensure that you go to jail." He told the coach to bet the team's entire prize money on winning. It worked. "We won the match," he says, and later it was "confirmed that bookmakers had tried to influence the players".
Mr Khan himself – like more than a few other international stars of his vintage – was caught up in a fuss over ball-tampering, when he admitted using a bottle top to scratch the ball during an English county game in 1981. But that was in a very different era, when lifting the seam or rubbing face cream into the ball were quite normal, and even at their worst of quite a different order of magnitude to a gambling conspiracy.
Fond memories of those days often prompt political adversaries to wish he would abandon his politics and revamp cricket. "If only," says Salmaan Taseer, governor of Punjab. "When he was captain, there was an iron discipline. He was the player, coach, board, everything. If he didn't get his way, he would threaten not to play."
But a return to the pavilion holds little appeal. "What is happening in cricket is what's happening at a micro-level in the country," he says. "It's the collapse of institutions. So that's not the answer. The country needs to build institutions and have the rule of law."
Politically, he eyes opportunity in the aftermath of the floods. Mr Khan is sometimes accused of a weakness for revolutionary rhetoric. But this time, he insists, there really is a movement in the making. "I'm an optimist," he says. "I hope that people will rebel against this callous elite, which has not even contributed to the relief effort. I think there will be street demonstrations."
Mr Khan's critics accuse him of being too soft on the Taliban. Former president General Pervez Musharraf once denounced him as a "beardless terrorist". He strongly opposes Pakistan's "war on terror" – which he says has ruined the economy, intensified terrorist attacks to "one every 24 hours" and radicalised the youth. His favoured solution of negotiations, however, is often criticised as naive.
Those views have alienated some Pakistanis, but fans still flock. Along the journey, cars wave him down, and urge him to pull over to the side. Excited men leap out to shake his hand and offer donations for his relief fund, securing a photo in the process.
Still, for all his goodwill, there are reminders why political success proves elusive. Reaching Rashakai, two hours outside Islamabad, he is surrounded by a human crush. Cameramen and reporters muscle their way forward. The speech is rousing. But there is still no sign of the rest of the convoy.
"Where are the trucks?" demands his sister, Aleema. "They've gone ahead without us," says a volunteer. Hours later, all managed to delivered their goods to 15 destinations. But when the cameras were switched on, Khan had turned up with six trucks short of a dozen.
To donate to the Imran Khan Flood Relief Fund: ptiuk.org/flood-appeal