Police were called by the ambulance service at around 1.15am on Thursday (May 2) after a man had been found with injuries inside a property on Charles Lane.
Officers attended and the man, since named as Michael Dale, 46, from Haslingden, was found with a stab wound to his chest. He was pronounced dead at the scene.
Five people were initially arrested by police on suspicion of murder.
Two men aged 30 and a 35-year-old man, all from Haslingden, have been released under investigation pending further enquiries.
A 38-year-old man and a 44-year-old woman, also from Haslingden, have been released no further action.
Detectives arrested a 37-year-old man, of no fixed address, on suspicion of murder on Saturday (May 4). Officers have been granted an extended period to question him.
Det Ch Insp Gareth Willis from Lancashire’s Force Major Investigation Team (FMIT) said: “We are continuing to question a sixth person in connection with the murder of Michael Dale.
“My thoughts remain with Mr Dale and his family at this sad and very difficult time. They are being supported by specially trained officers.
“We continue to appeal for information about Mr Dale’s murder. We are particularly keen to speak to anyone who saw anything unusual or anyone acting suspiciously, in the Charles Lane area, in the early hours of Thursday morning.”
Anyone with information can call police on 101 quoting log 0062 of May 2.
Alternatively, you can reach Crimestoppers anonymously on 0800 555111 or online at crimestoppers-uk.org.
A Home Office post mortem examination has taken place and the cause of death established as stab wounds.