(PTI)Mumbai: The CBI has sealed the Brady House branch of Punjab National Bank in Mumbai. The Brady House branch has been the nerve centre for a skein of fraudulent transactions that have so far affected Rs 11,400 crore. Gitanjali Gems - owned by Mehul Choksi, Nirav's maternal uncle and also embroiled in the country's biggest banking fraud - said three top officials of the company had resigned. 'Conscience' letterIn a regulatory filing, Gitanjali Gems said Karkare had resigned citing personal reasons. The Gitanjali Gems stock sank almost 10 per cent to close at Rs 33.80.