A man has been arrested by police investigating a serious assault in Boston at the weekend.
The man, aged 35, was arrested on suspicion of causing grievous bodily harm with intent.
He has since been released under investigation.
A man in his 40s remains in hospital with serious head injuries after the incident.
Police were called to an altercation near to the Assembly Rooms involving a large group of men and women at just after midnight on 2 September.
They continued their argument across the road to near Town Bridge where the man in his 40s suffered serious head injuries.
Police would like to speak to anyone who witnessed the incident to contact them via 101 using the reference number 6 of the 2 September, or to e-mail firstname.lastname@example.org - with the reference in the subject box, or anonymously through Crimestoppers, on 0800 555 111 or online at crimestoppers-uk.org.