I just found this in a book review for a book entitled Indo-Bangla
Mistrust:

The Tin Bigha Corridor is no larger than a football field. The
Nehru-Noon accord of September 3, 1958 provided for a straightforward
exchange of enclaves between India and East Pakistan. A formal
agreement was signed thereafter on September 10, 1958. Besides the
exchange, Berubari was to be split horizontally and equally. But the
notification in respect of Berubari was never issued by India. Under
the 1974 accord between Indira Gandhi and Mujibur Rehman, India agreed
only to lease in perpetuity to Bangladesh an area of approximately 178
metres by 85 metres near Tin Bigha to connect Bangladesh with its
enclave Dahagram. Agreement on the terms of the lease was reached in
1982. Only in 1992 could it be implemented.

The same holds good for the two newly formed tiny deltaic islands
which India calls New Moore and Bangladesh calls South Talpatty. They
were discovered by a U.S. satellite in 1974 and became an issue in the
maritime boundary talks in 1979. Bangladesh claims that in May 1979
Prime Minister Morarji Desai agreed with the Deputy Prime Minister of
Bangladesh, who had called on him, to hold a joint survey. However, on
April 9, 1980 Indira Gandhi claimed that the islets belonged to India.

They lie at the mouth of the Hariabhanga River which
separates the two countries. They are mudflats with no human or animal
life. In 1974 India and Bangladesh signed an agreement on the
demarcation of the land boundary between the two countries. A maritime
boundary agreement is yet to be concluded. It will define Bangla-
desh's Exclusive Eco-nomic Zone (EEZ), sandwiched as the country
is between India and Myanmar.