The embassy said he handed over the letter of credence to the King at the Royal Palace in Madrid on Wednesday.
He conveyed the greetings of President Md Abdul Hamid and Prime Minister Sheikh Hasina to the King, and briefed him about Bangladesh’s socio-economic development.
Khandker was the longest serving head of Bangladesh Police before retiring last year.
He was appointed as Bangladesh’s envoy in August this year for three years, cancelling his post-retirement.
Khandker studied English literature at Dhaka University and joined the police in 1984.
He is a recipient of the Bangladesh Police Medal and the President Police Medal.
