The operation led to the recovery of a factory-made pistol, cash in both Indian and Bangladeshi currencies, and other incriminating items.
Abdur Rashid was declared a foreign national by the Foreigners' Tribunal in 2016 while, Mohammad Khairul was declared a foreign illegal foreigner in 2015.
Joint Commissioner of Police, Delhi, Sanjay Kumar Jain said, "Immigrants were transferred from Bangladesh through the northeast before being moved to major cities like Delhi."
A case has been registered against the three personnel, and Hailakandi SP Leena Doley has initiated a high-level probe into the incident.
He had been admitted to SMCH after reportedly falling ill but managed to flee the premises by taking advantage of the situation.
The operation, part of Assam’s ongoing efforts to secure its borders, received praise from Chief Minister Himanta Biswa Sarma.
The 3 Bangladeshi nationals were identified as Masum Khan, Iqbal Hussain and Mujanur Rehman.
The arrest, which took place near the Dharmanagar railway station a day ago, highlights the growing concerns surrounding border security
Currently, there is a night curfew imposed along the Meghalaya-Bangladesh border in view of Bangladesh's ongoing turmoil
In the last two months around 105 infiltrators have been arrested in the Agartala Railway Station.