Evil rapist Larry Murphy, who is the chief suspect for the murder of Deirdre Jacob, has been working on building sites in England as the DPP continues to decide whether to charge him in the missing Kildare woman case.
"Gardai are aware of where Murphy is living in the London area and are aware that he has been working as a carpenter on building sites," a senior source told the Herald.
In late February, officers submitted a file to the DPP on the murder of trainee teacher Deirdre, but a decision to charge Murphy has not yet been made.
In the meantime, gardai continue to work with English pol-ice in "discreetly monitoring" Murphy.
"The Deirdre Jacob investigation is at a very delicate stage at the moment. It is a case that is mainly based on circumstantial evidence, but huge work has been put into the file," the source said.
"Larry Murphy is a person of interest in this murder investigation, and because of this, gardai have made sure they are aware of his location in the UK and his activities."
If the DPP decides Murphy has a case to answer, gardai will secure a European Arrest Warrant for his detention.
The investigation is being led by gardai based in the Kildare division under the command of Superintendent Martin Walker.
Deirdre (18) was last seen on July 28, 1998. Her disappearance was treated officially as a missing persons case until Aug-ust 2018, when it was upgraded to a murder investigation.
The decision to reclassify the case followed the emergence of new information, which led to gardai opening up fresh lines of inquiry.
One of Ireland's most reviled criminals, Murphy (54), from Baltinglass, Co Wicklow, was convicted in 2001 of kidnapping, repeatedly raping and attempting to murder a young woman in the Wicklow mountains in February 2000.
He was released in 2010 after serving 10 years, mainly in Arbour Hill Prison.
Deirdre was last seen on July 28, 1998, near her home at Roseberry, Newbridge, Co Kildare, at around 3pm.
She had left home at around 1pm to go to Newbridge.
She was seen at the AIB on Main Street at 2.20pm before crossing the street and going to the Post Office at 2.30pm.
The last CCTV footage of her was recorded from an Irish Permanent office, also on Main Street, as she walked back in the direction of her home.
Murphy became a person of interest to detectives after it emerged he had visited the shop owned by Deirdre's grandmother.
CCTV footage from the day of the disappearance has been digitised, resulting in new witnesses being identified.
During a garda interview while in prison, Murphy denied any involvement in Deirdre's disappearance.
Gardai travelled to Britain in 2018 and, in the company of the London Metropolitan police, attempted to interview Murphy, but he refused to answer questions.
"Murphy is an extremely talented carpenter and he has been using his skills at building sites in London and Birmingham," a senior source said.
"He has not come to the att- ention of police in the UK for any criminal offences."
It previously emerged that two retired detectives who secured critical testimony from a prisoner who implicated Murphy in Deirdre's murder were interviewed by gardai and their statements have been included in the file sent to the DPP.
The prisoner said Murphy confessed to the murder while he was serving a sentence for rape.
Last July, on the 21st anniversary of her disappearance, Deirdre's family said they were confident gardai were making progress.
Her father, Michael, said they have been able to "inch the case further, little by little".
"We have always been positive, because you have to be - if you don't hold a positive outlook, the world collapses around you," Mr Jacob said.