New Delhi, June 16 -- Bangladesh protested against the treatment of an adviser to Prime Minister Tarique Rahman, who was reportedly detained and questioned for several hours at New Delhi airport.

In the latest diplomatic row between the neighbours, the foreign ministry summoned Indian Deputy High Commissioner Pawan Badhe and expressed its "deep disappointment" over the incident.

Badhe arrived at the foreign office in the afternoon when he was handed over the protest letter, Foreign Ministry spokesman Shahidul Karim said.

Earlier, Foreign Minister Khalilur Rahman described the incident as "unexpected and unfortunate", while Dhaka formally conveyed its concerns to Badhe.

Bangladesh government strategy adviser Zahed Ur Rahman was stopped...