Valerie, a mother and grandmother, was found murdered in her bedroom in Smugglers Lane, Bosham, on 30 December 2013, police said.
She had been staying at the property while its owners were away over the Christmas period, according to police.
The brutal murder sparked a detailed investigation, including an exhaustive forensic search of the crime scene, police said.
Sussex Police has repeatedly appealed for information from the public over the years – with the most recent appeal coming in December 2018 on the fifth anniversary of Valerie’s death.
Today, police announced that a man has been arrested in Romania on suspicion of the murder.
Sussex Police had previously stated that it was ‘determined’ to find Valerie’s killer and to ‘get justice for her and her family’.
In the first year following the murder, officers interviewed more than 9,500 people, of which 8,000 were during the house-to-house enquiries and taken 580 statement as part of the investigation, a spokesman said at the time.
In 2015, police launched the biggest voluntary mass DNA screening in its history, asking all men aged over 17 who live, work or visit Bosham to provide a DNA sample to eliminate them from the inquiry.
According to police, this meant that by December 2018, detectives from the Surrey and Sussex Major Crime Team had taken 2,819 DNA samples from men from Bosham or associated to the enquiry in some other way.
An inquest into Valerie’s death held in 2016 heard that the 55-year-old had been discovered dead at the Bosham home by her sister, Janet Graves.
Valerie, who had recently moved from Scotland to Bracklesham Bay to care for her elderly mother, was found to have ‘severe head injuries’, the inquest heard.
A BBC Crimewatch appeal screened in 2014 detailed how Miss Graves had spent Christmas Day, which was also her birthday, celebrating with her family – including her children Tim Wood and Jemima Harrison, and her grandchildren.
In the programme, Tim described his mother as a ‘big kid at heart’. “She loved playing with the grandkids and messing around being silly,” he added.
Miss Graves’ mother Eileen, sister Janet and Janet’s partner Nigel Acres were all in the house the night of Valerie’s death, according to the programme.
Cristian Sabou, 28, a Romanian national, was arrested this morning at an address in Dej, Romania, after a European Arrest Warrant (EAW) was served, police said.
His extradition is being sought through the Romanian courts and he will now appear court in Cluj-Napoca to face extradition proceedings, police confirmed.
Police are now hoping to ensure, subject to the decision of the Romanian courts and judicial authorities, Sabou’s return to this country for an appearance before magistrates, with a view to him being sent for Crown Court trial.