Contact Crimestoppers, anonymously, on 0800 555111.
Below is a picture of Adi shared by his family.
Update, 9.50am, 17 January
A 35-year-old man has now been charged with grievous bodily harm wounding with intent in connection with the incident in Witham Street, Boston.
Maksim Iliev of Union Street in Boston will appear in court later today.
Update, 4.09pm, 16 January
A 35-year-old man has been arrested on suspicion of grievous bodily harm wounding with intent in connection with the serious assault in Witham Street, Boston.
He was arrested in the Luton area and remains in police custody where he will be questions in due course by detectives.
The investigation is ongoing, and we continue to ask for anyone we have not yet spoken with to come forward.
Original release, 7.44am 15 January
A man has been taken to hospital following an assault in Witham Street, Boston.
Officers were called to Witham Street just before 11pm on Sunday, 14 January, following a report of a fight outside of the Carpenters Arms. A man in his 30s has been taken to hospital with injuries described as serious.
As part of our investigation, we are appealing for anyone with information that will assist our inquiries to get in touch. We would like to speak to anyone who was in the area and witnessed the incident or has recorded video footage from a dashcam, mobile phone or other recording device.
Anyone who can assist is asked to email or call the Investigating Officer by calling 101 or email [email protected], please quote incident 376 of 14 January.