A 26-year-old antheral has been arrested successful Dublin connected suspicion of the execution of 22-year-old Mary Ward successful southbound Belfast.
Ms Ward, 22, was recovered dormant by constabulary astatine her location successful Melrose Street connected 1 October.
The Police Service of Northern Ireland (PSNI) has since started a execution investigation.
Assistant Chief Constable Davy Beck said the probe was progressing astatine gait and constabulary were inactive trying to found the nonstop circumstances of Ms Ward's death.
An Garda Síochána (Irish police) said it would proceed to enactment intimately with constabulary successful Northern Ireland.
Timeline
Ms Ward died from a fig of wounds to her neck, BBC News NI understands.
Her assemblage was recovered by constabulary officers who went to her location connected Tuesday 1 October – but it is believed she was killed connected oregon astir 25 September.
The PSNI had been interaction with her connected a fig of occasions successful the weeks beforehand.
This began connected 4 September erstwhile she made a ailment to the constabulary astir being the unfortunate of violence.
The past interaction it had with the mother-of-one was connected 25 September.
Details of the execution probe were not released until conscionable earlier midnight connected Monday.
It is believed the PSNI had determined a fig of days agone that Ms Ward had been murdered.
Police judge Ms Ward was past seen live connected 25 September.
Police Ombudsman
Police confirmed connected Tuesday that pursuing a reappraisal of its erstwhile engagements with Ms Ward the lawsuit had been referred to the ombudsman.
The Police Ombudsman's Office said the absorption of its probe would beryllium connected the constabulary effect to a study of unit successful the weeks starring up to her death.
It confirmed the lawsuit was referred to it by constabulary connected Sunday night.
Violence against women
Head of nationalist extortion branch, Det Ch Supt Fisher, has said Ms Ward was the 4th pistillate to beryllium killed successful Northern Ireland successful the past six weeks.
Combating unit against women and girls (VAWG) has been rising up the database of constabulary and governmental priorities recently.
Two years ago, the PSNI launched an enactment plan.
This was followed by an Executive Office strategy published past month, external.
It is successful effect to the information much than 30 women and girls person been murdered successful Northern Ireland successful the past 5 years.
In the 12 months to July, the PSNI recorded 22,400 VAWG-related offences.
The PSNI has said this is simply a 16% driblet year-on-year and shows immoderate advancement is being made.
However, it accepts determination is inactive overmuch to beryllium done by it – and wider society.