A man remains in hospital after being lured into what is believed to have been a fake taxi and badly beaten up.
Officers were called to The Prince of Orange pub, Carr House Road, Shelf at 2.30am following reports of a seriously injured man.
Detectives believe the victim accepted a lift from outside the Dixy Chicken takeaway on Morley Street, Bradford at 1.40am.
The man was later assaulted on Cooper Lane by a man and a woman, who also stole his moble phone and wallet.
As a result of the attack, the man was taken to Bradford Royal Infirmary with serious facial injuries, including a broken jaw.
DI Gary Stephenson of Calderdale CID, said: “This was vicious attack against a man with a completely unnecessary level of violence used.
“Thankfully this level of violence is rare in Calderdale and we are doing everything we can to bring those responsible to justice.
“I want to hear from anyone who witnessed the victim getting into the vehicle, the actual assault or when he was left in Shelf.
“We are particularly keen to speak to anyone who saw the vehicle involved as one line of our investigation is that the occupants of it were pretending the car was a taxi.
“I would always urge anyone using taxis to either flag down a black cab or to book a taxi through a known and reputable firm.”
An investigation has been launched into the incident and officers want to speak to a man and woman in connection with the incident.
The man is described as of stocky build and possibly Eastern European. The woman is described as being white and dressed in denim shorts and with short brown bobbed hair.
It is thought the vehicle involved was a silver coloured 5-door vehicle.
Any witnesses to the incident are asked to contact DC Darren Heald of Calderdale CID on 101.