Tanzil Ahmad, an officer of the National Investigation Agency (NIA) died after unknown assailants pumped 21 bullets into him while he was returning from a wedding in Uttar Pradesh's Bijnor district after midnight on Saturday. Police termed the killing a planned attack.
Ahmad, 48, known for undercover operations, joined the NIA in 2010.
Union Home Minister Rajnath Singh, in Lucknow, said the death was being probed.
The shooting in Bijnor district took place when the officer, an assistant commandant in the Border Security Force (BSF) and on deputation with the NIA as an inspector since 2010, was returning from a wedding with his wife and children. His wife Farzana received four bullet injuries, but his children were unharmed.
Rajnath Singh, speaking on the sidelines of a function in Lucknow, said: "I have spoken to the officers concerned. Our teams have gone there to probe the matter and they will submit a comprehensive report very soon."
The officer was laid to rest with full state honours in Shaheen Bagh area of south Delhi.
NIA spokesperson Sanjeev Kumar said in Delhi that Ahmad was a "martyr".
"He will be given all dues that is given to someone killed in service," Kumar told IANS.
An official statement issued by the NIA termed the death a "great loss".
"Tanzil Ahmed was an asset to the agency. His killing is a great loss to NIA. We take it as a challenge to bring the perpetrators of this crime to justice. We will not rest until that happens," the statement said.
"The assailants came on motorbikes and opened fire from a close range on Ahmad near Sahaspur town," Sanjeev Kumar told reporters earlier on Sunday.
The Uttar Pradesh police said they were working "on all angles" to find out the motive behind the killing of Ahmad.
His wife is undergoing treatment at Fortis Hospital in Noida.
"Nothing can be ruled out now until and unless we get absolute concrete evidence. We have to work on all angles. We have to see it from all the sides and work out the case," Daljit Chowdhary, additional director general of police, Uttar Pradesh, said on Sunday.
He said borders have been sealed, nearby areas are being searched and senior officials from Anti-Terrorist Squad (ATS) have been put on the job to track the assailants and probe the attack.
"I am very hopeful that we will work out the case and arrest the accused. It looks like a planned attack. It was definitely not a robbery," Chowdhary said.
The NIA termed Ahmad's killing a "planned attack".
"A planned attack took place on him when he was fired upon and killed," NIA spokesman Kumar said. "He (Tanzil) was assistant commandant with BSF and currently on deputation with NIA. He was with us for last six and half years."
The investigating agency is trying to find out how he was tracked by his assailants.
"The patient has been brought in a critical condition. Our doctors are providing the best medical treatment to treat the patient. As a matter of patient confidentiality we cannot comment anything further," a statement from the Fortis Noida said.
Ahmad was pronounced dead on being taken to a medical facility in Moradabad. His body was later brought to Delhi.
Before joining the NIA, Ahmad was part of the in-house team of BSF, providing vigilance cover. He also held tenures as instructor at BSF Academy at Tekanpur, near Gwalior, and training centre at Hazaribagh.
