As the furore over Javed Hashmi's recent arbitrary arrest continues to excite and anger the opposition, another political prisoner has just completed seven years of incarceration without being convicted of any crime.

Regular readers of this column will be aware that I wrote often and at length about the allegations of deals and scams that swirled around Benazir Bhutto, particularly during her second stint in office. At the centre of these scandals stood Asif Ali Zardari, the prime minister's husband. Many PPP leaders privately assert that he is the man who brought their government to a premature end with his voracious appetite for the quick buck. Others say that Benazir Bhutto was an equal partner in her spouse's free and easy ways with other people's money.

In and out of office, as well as in and out of the country, Ms Bhutto has stoutly defended her husband, insisting that he is a wealthy businessman in his own right, and made all his money legitimately. Asif Zardari's friends who knew him in his bachelor days beg to differ: they talk about a young man perpetually strapped for cash, and whose tastes far outstripped his financial resources. From a broke, young, would-be playboy to the owner of 'Surrey Palace' is quite a step, and one that cannot be simply credited to business acumen.

However, mere suspicions unproven in a court of law cannot be the basis of endless incarceration. If that were to become the practice, all of us could have thousands locked up. We all know people who clearly live far beyond their known means. But instead of being stigmatized or called to account, they are generally looked up to and cultivated by a society that admires wealth and does not want to examine closely how it was acquired.

The Gujrat Chaudries are a case in point: while widely alleged to be recipients of vast loans improperly sanctioned by cooperative and commercial banks, they are courted not just by their many hangers-on, but by the president himself in his quest to cobble together a workable alliance to support him.

I know many readers will protest and say that Asif Zardari is a crook and deserves to stay locked up. But our legal system is based on the presumption that a person is presumed innocent until proven guilty. Thus, the onus of establishing Mr Zardari's guilt is on the prosecution which has failed in proving even a single one of the fourteen or so cases against him. The one case in which he and his wife were declared guilty by the Lahore High Court was thrown out by the Supreme Court when it was established that the judge was blatantly and disgracefully pressured to return a 'guilty' verdict by Nawaz Sharif and his henchmen.

After a Swiss court's verdict against the couple, even the most ardent PPP supporter will have some doubts about their fiscal integrity. However, the fact remains that Mr Zardari has been granted bail in almost each case for which he is being tried in Pakistan. Keeping him in custody has little to do with the law, but everything to do with politics.

Recently, Mustafa Khar revealed on a private TV channel how brutally Zulfikar Ali Bhutto had been treated by his tormentors in his last few hours. That he was hanged on a split 3-4 verdict is an indication of how blatantly dictators bend the law to suit themselves. Zardari's continued incarceration is a reminder of the same mindset. No other politician in Pakistan's history has served a longer spell in jail.

Apart from the unfairness of the treatment meted out to him, it would seem that there is one law for politicians from Sindh, and another one for those hailing from Punjab and the NWFP. Both Nawaz Sharif and his brother Shahbaz are sitting in comfortable exile abroad despite the fact that in comparison to their alleged corruption, Mr Zardari's activities pale into insignificance. Mr Aftab Sherpao, despite the serious charges the National Accountability Bureau had against him, is a federal minister. These are just two examples; many more are as well known.

I must confess that one reason I am taking up cudgels on Asif Zardari's behalf is that I have a sneaking admiration for the humour and courage he has displayed during his seven years in jail. Despite his ailments and separation from his family, he has not whined about the injustice of it all, nor has he tried to cut a deal, although apparently one was on offer: he would be released and allowed to go abroad if he and Benazir Bhutto promised not to return for a few years. Indeed, as a prisoner he has behaved with far greater maturity and poise than he displayed when he was a free man.

Now we all know that Asif Zardari is hardly a political heavyweight the army would fear enough to lock up and throw away the keys. By himself, he is no threat to Musharraf. But he is a useful lever against Benazir Bhutto and the PPP. As long as he is in prison, Gen. Musharraf's advisers feel that his wife and her many supporters will be kept in check.

In most countries where the rule of law is in force, Zardari would have been freed on bail long ago. His passport could be withheld while the legal cases proceeded, but few independent courts would have permitted such blatant political victimization. Indeed, most superior courts would have taken suo motu cognizance and ordered that bail be granted and the prisoner released.

His many detractors will no doubt say that just because of the inefficiency of the legal system, Zardari should not be allowed to go free. It is true that it is very difficult to prove corruption cases, which is why so few politicians and bureaucrats have been convicted. Virtually no judges and military officers have even been charged. So why should Zardari rot in jail while so many others walk free? Indeed, NAB's highly selective use of its powers has made a mockery of the whole accountability process.