Police have formally identified a man who died last week in Inner Street, Grantham, as Ian Addison, who was in his 40s.
Police launched an investigation into the death of Mr Addison after he was pronounced dead on January 20.
The Coroner has opened and adjourned an inquest pending further enquiries.
A 20-year-old man and a 31-year-old woman, both from Grantham, were arrested on suspicion of murder following a report of a collapsed man at Inner Street at 12.38am. Mr Addison was taken to hospital for treatment but was later pronounced dead.
The cause of his death is currently being treated as unexplained.
Officers would like to hear from anyone who may have been in the area around the time in case they have information that is relevant to the enquiry. Anybody with information should call the non-emergency number 101 quoting incident 9 of January 20.