A man was seriously injured in an assault in Brighouse town centre.
The 24-year-old was attacked outside a pub on Bethel Street at around 1.30am on Saturday, August 8.
Detectives have now released CCTV images of three men they would like to speak to in connection with the incident.
Det Con Marcus Southwell, of Calderdale District CID, said: “I would appeal to anyone who can identify the men pictured, or who has information about the incident to come forward.
“Although the assault took place in the early hours of Saturday morning, there were still a number of people in the area, who may have witnessed the incident itself and may hold vital information which may help in bringing those responsible to justice. Enquiries are ongoing.”
Anyone who can identify the men pictured or who has information about the incident should contact Calderdale CID via 101, or alternatively Crimestoppers, anonymously, on 0800 555 111.