Rather than asking why India's external affairs minister is assisting Modi with his travel documents, the simpler question might be, why is Modi – who is being described as a 'fugitive' from the law – being allowed to travel at all?
What has Lalit Modi been accused of?
Lalit Modi was the founder of the wildly successful Indian Premier League and an administrator in the Board of Control for Cricket in India prior to that, two jobs that required plenty of political manouevring and involved huge amounts of cash. In September 2013, after being kicked out by the BCCI, Modi was found guilty and banned for life by the board of being involved in a number of questionable activities while running the IPL including rigging bids, arm-twisting franchies and awarding contracts without the board's permission.
Alongside the BCCI's investigation came an investigation by the Enforcement Directorate into alleged violations of the Foreign Exchange Management Act, suggesting Modi had acquired potential foreign exchange outside India illegally. By this time Modi had already left the country. Modi has always denied all the charges, although he has refused to personally present himself before either the BCCI disciplinary board or the ED, claiming he stays away from India because there is a threat to his life.
What is Modi's legal status, i.e what's all this stuff about blue corners?
In 2010, according to a report in Mint based on an unnamed source, the Enforcement Directorate had issued a "blue corner notice" against Modi. Interpol notices, like blue corner ones, are international alerts used by police across country lines to communicate information. Blue corner notices specifically ask authorities of various countries to locate, identify or obtain information about someone involved in a criminal investigation, although they don't go as far as a "red corner notice", which asks international police forces to arrest the accused people if they are identified.
A little while later, Modi's passport was also revoked after he repeatedly fail to turn up when summoned by the Enforcement Directorate, with the Passport Office pointing out that his ability to move about was detrimental to "public interest" because of the disrepute he has brought to cricket.
But that was years ago – how can he stay in the UK if he doesn't have a passport?
First, it is possible to remain in the United Kingdom even without an existing passport. As long as Modi has a valid document to enter and remain in the UK, such as a visa, he is allowed to stay there. Moreover, last year, the Delhi High Court restored Modi's Indian passport, saying the officer who revoked it had no right to do so.
In its order, a bench chaired by Justice Badar Durrez Ahmad, concluded that the "public interest" argument that was used by the passport officer with reference to the importance of cricket did not fall into the categories that permitted the revocation of a passport. This meant that by revoking his passport, the government was taking away his liberty as a citizen of the country – an action the court said was invalid.
Shouldn't a man under criminal investigation be required to come to India if summoned?
The High Court in its order restoring Modi's passport pointed out that he doesn't need to be in India to provide evidence, since he has offered to do so via Skype. "A request for an alternative mode examination under video conferencing was certainly an option available with the Directorate of Enforcement and should not have been simply shrugged aside," the court said.
As far as the blue corner notice goes, the only requirement for the British government is to provide information to Indian authorities – which, considering Modi's whearabouts are well-know, one presumes they have done. Modi had also initially raised concerns about not having received the notice and the order regarding his passport in the High Court doesn't make any mention of an international notice, which might have bolstered the government's case.
How does Sushma Swaraj's letter come into play?
Any government has a set of options when it comes to its own citizens who are abroad, not all of which are necessarily legal. Political approaches, like telling the United Kingdom that India would take issue with a travel certificate being issued to an accused Indian citizen, can work towards limiting his ability to move around and evade further summons. Swaraj essentially did the opposite – she said that India would have no issue with Modi being issued a travel certificate based on the UK's rules and regulations.
Crucially, Swaraj told the UK this even before the High Court had passed its order restoring Modi's passport. Considering there are questions about conflicts of interest between Swaraj and Modi, whose lawyer was the minister's daughter, it is evident that only did the government fail to use one of the political levers it had available to itself, it pushed the lever in the other direction altogether.
What does all that mean?
Effectively it means that this government doesn't really consider him a fugitive. Authorities can detain him if he comes to India, because he hasn't turned up at repeated ED summons, but it couldn't revoke his passport as a result of that. The ED could issue a red corner notice, which would encourage the UK to arrest him, but they haven't done that yet. Now, with the External Affairs MInister even telling the British government that it isn't concerned about him traveling in and out of the UK, allowing him to get a travel document until 2016, it is clear that authorities either don't have the material on record or the political will to take further action from a man being described as a "fugitive."