Shane Fox, 26, was fatally stabbed in the chest in Nest Farm Crescent, Wellingborough, in the early hours of Saturday, December 1.
His mother, Caroline, claims Northamptonshire Police were going to release his body in time for a funeral before Christmas but there was a delay.
"When we did eventually get him, we couldn't touch him or kiss him because they kept him for so long," said Mrs Fox.
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"It sounds weird but we were looking forward to saying goodbye, to touch him and give him a kiss. We've been left in the dark all the time."
The family has submitted a formal complaint to the force in relation to its handling of the situation.
They held a funeral on January 11 after the body was returned on January 7.
The investigation into Mr Fox's death is still ongoing after a 22-year-old man arrested in December was released on bail pending further enquiries and a 39-year-old man arrested the day after the attack was released without charge.
Detective Chief Inspector Ally White, from the East Midlands Special Operations Unit Major Crime Team, said: "The inquiry into the murder of Shane Fox in December 2018 is ongoing and we are continuing to investigate a number of lines of inquiry.
"Specialist Family Liaison Officers are continuing to support Shane’s family and are in regular contact with them.
"As with any murder investigation, we understand the wishes of victims’ families to hold a funeral for their loved one as soon they are able to.
“We always try to enable this in a short a time as possible, usually within a few weeks; however, it can take longer depending on the circumstances.
"In this case, we were able to give authorisation by the end of December.
"Our Professional Standards Department has received a formal complaint in relation to this and, as such, we are unable to comment further at this time."
Mr Fox returned to Nest Farm Crescent at about 2am having come from the direction of Nest Farm Road.
He walked across the grassed area and footpath leading to the flats where he lived.
He was near the car park when he was stabbed.
Another man that Shane was with was also stabbed in the chest and taken to hospital with a superficial wound.
"This is very much an active investigation and we are still keen to hear from anyone who may have any information about Shane’s murder and what happened in Nest Farm Crescent, Wellingborough, shortly after 2am on Saturday, December 1," said DCI White.
"I would urge anyone who has any information they believe might be relevant to the investigation, however small or insignificant they think it might be, to get in touch with police.
"Please call Northamptonshire Police on 101 and ask for the Operation Talbot incident room or, if you prefer, you can contact Crimestoppers in confidence and anonymously on 0800 555111.
"You can also contact us online by visiting the Major Incident Public Portal at MIPP.police.uk and clicking on the box headed ‘Northamptonshire Police Request for Information – 'murder of Shane Fox' in the Incidents section."