Buxar central jail is the sole provider of rope for capital punishment in north and eastern India, its superintendent Surendra Kumar Ambastha said.
"We had supplied a special rope for hanging Afzal Guru to Delhi's Tihar jail on order in 2007," Director, Bihar Prison Department, SBP Singh said.
This rope was, however, not used because of the stay on Guru's execution and might have been used for Kasab, the authorities and inmates of Buxar prison feel.
"Since no requisition had been sent for preparing rope for Kasab, it cannot be said with authenticity if it is the same rope the Buxar jail had supplied to Tihar for Afzal Guru," Singh said.
Buxar jail had also provided the rope for the execution of Dhananjoy Chatterjee in Kolkata in 2004, he said.
Ambastha said specially trained inmates of Buxar jail manufacture the rope using a special synthetic jute supplied by National Cooperative Consumers' Federation of India Limited, the apex federation of the consumer cooperatives in the country.
The rope is manufactured in a way that there is least friction and the knot tightens smoothly, Jailor, Buxar prison, Manoj Kumar Sinha said.
Sinha said the rope used for hanging takes over a fortnight to be made after requisition.