No, he would not say how he reached Britain, only that he left Saudi Arabia last month. Too many people would be endangered if details emerged. The Saudis had taken his passport when they arrested him last year and subjected him to six months' interrogation. But there were ways to obtain another one.
In the al-Hayer jail for political prisoners south of Riyadh they questioned him daily about the organisation of academics for which he was spokesman, the Committee for the Defence of Legitimate Rights.
'The interrogators wanted to know who were its leaders, who was behind it, how many members it had, how they contact each other - and if its aim was to undermine the regime.'
Such is the nature of the Saudi regime, and swelling resentment of its ruling family, that these were natural questions to ask. What was this movement, and how widespread was it? Was it just a clique of disaffected university academics and Islamic scholars? Or did it represent a serious threat to the existing order?
The committee is one manifestation of the religious opposition in Saudi Arabia. King Fahd has had to balance modernisers who seek liberal political reforms with Islamic puritans who think that the country is liberalising too fast and that it should revert to strict Islamic orthodoxy.
Dr Masari's group bridges the two. It seeks respect for human rights based on Islamic values, but uses the language of liberalism. 'We want freedom of speech and freedom of association.' His associate, Saad al- Faqih, who studied keyhole surgery at Liverpool, explained in general terms. 'Most people agree that Islam should be adopted as a way of life for both the state and for individuals.'
They were not opposed to a monarchy, nor hellbent on establishing an Islamic caliphate. But: 'Rulers should be acceptable to the people. The monarchy is acceptable as an alternative to chaos. We can live with the king so long as he gives us basic rights.'
They were highly critical, of the royal family. 'They believe they own the land and the people above the land. If they don't make reforms they will collapse.'
As for the much vaunted Majlis al-Shura, the consultative council appointed by the King as a belated effort to widen the participation in decision making: 'The majlis is a joke.' Even those loyal to the king were disappointed that the fact that the majlis was meeting was not disclosed - hardly a move towards open government.
Dr Masari and Dr Faqih felt that the royal family had become even more autocratic, suspending the tradition by which a subject could appeal directly to the monarch by sending a personal cable. And their own activities were hampered on the grounds that they threatened to sow discord.
The dire predictions that the Saudi regime would collapse under the weight of the corruption of the ruling family have not so far materialised. The House of Saud is still on the throne. The tribal dynasty founded by King Abdelaziz al- Saud (known in the West as Ibn Saud) has survived an uprising in Mecca by zealots in 1979, a Shia rebellion in the eastern province and the threat of invasion.
It has survived mainly by largesse. Whatever the grumbles, however much the oil wealth has been squandered by dissolute princes, the general population has benefited. All have a share, however disproportionate, in the country's riches. Saudis can look around at other states which have enjoyed huge oil revenues, such as Iraq and Libya, and count their blessings. Better an arrogant and feudal autocracy, based on family and tribe, than a dictatorship justified by a spurious ideology and propped up by a brutal security apparatus.
For, Dr Masari's experience notwithstanding, Saudi Arabia is a place more of moral oppression than political repression. The bans on alcohol, on women driving or working, on places of entertainment, on Christian worship, are all restrictive. But arbitrary arrest and torture are rare, and the mass executions of political opponents are not a feature of Saudi life. Saudis seeking the pleasures of the West are free to leave as they choose. Governors have their tribal majlis, where plaintiffs can air their grievances.
Yet the Saudi royal family remains paranoid. It allows no criticism in its tightly controlled media. Western journalists are rarely admitted. Outside, it has been busy buying up the Arabic press in London and elsewhere, less as a mouthpiece of Saudi policy - there is none - than to gag criticism of the kingdom.
Saudi hands have been seen in the spread of militant Islam. Ten days ago, the Saudi news agency carried a brief item stating that Osama bin Laden had been stripped of his citizenship. This extraordinary measure, comparable to the treatment meted out to dissidents by the Soviet Union in the old days, was taken by the Prime Minister, who happens to be King Fahd. The object of the stricture had already been disowned by his family, the largest contractors in the realm.
Bin Laden had been identified in the Egyptian press in past months as the leading sponsor of Islamist extremists. He had previously been active in Peshawar, helping Arab fighters with the Afghan mujahedin. Over two years ago he moved to the Sudanese capital, Khartoum, where he has a construction company and enjoys the company of that multinational band united by Islam of former fighters in Afghanistan.
Saudi Arabia remains one of three key Western allies in the Middle East. It was the key to the Gulf war coalition against Iraq. It has a quarter of the world's oil reserves. And it is a huge market for Western, arms and other goods.
So long as it provides a cheap and plentiful supply of oil, and a market for the West, foreign policy-makers are likely to ignore the voices warning of worrying developments on the kingdom's borders or lack of human rights, and make hay while they can.
Sunday Review, Books