Five men were arrested today by the PSNI about murders and an attempted murder linked to the feud between the UVF and LVF.
Two men in their 30s were arrested in north Belfast over the killing of Stephen Paul (28), who was shot at the end of last month. He was gunned down outside his home off the Crumlin Road in north Belfast.
One of the men was released without charge tonight. The Police Service said the other man remained under questioning.
The UVF is believed to have carried out both killings believing their targets were connected with the LVF.
A number of other people have previously been arrested for questioning about the murders - all have been released without charge.
The feud has so far claimed the lives of four men.
It was revealed today that Mr McCausland had been facing a series of burglary and theft charges. They were formally dropped in Belfast Magistrates Court today when the crown told the court he had been killed.
Meanwhile two men were arrested about the shooting of a taxi driver in Newtownards, Co Down at the weekend. The taxi driver was shot several times in the upper body after dropping off a fare in the West Winds Estate on Saturday night. That shooting too is believed to be linked to the feud.
Police said tonight a 40-year-old man has been charged with membership of the Ulster Volunteer Force by police investigating serious terrorist crime in North Antrim. He is due to appear at Ballymena Magistrates Court tomorrow.
Another man was detained and was being interrogated about the murder of Craig McCausland (20), who was shot dead by three men who burst into his home at Dhu Varren Park, also in the north of the city, earlier in the month.