Sources in the MEA said apart from blocking the visa stickers, officials at all entry points have been given the serial numbers of the visas, that were stolen on September 3, to prevent any illegal entry by their use.
They said it has also been decided that all diplomatic bags would be received by an Indian High Commission official and not by the clearing agent, as is the practice at present.
The High Commission in London was informed by the clearing agent that four Category 'B' diplomatic bags, including three bags that contained 6,000 visa stickers, have been stolen during transit from the Heathrow Airport to India House in Aldwych, central London.
The bags were being transported from the Heathrow Airport by the clearing agents, who handle 'B and 'C' category diplomatic bags of the High Commission for the last several years.
The High Commission has already registered a case with the London police.