Van der Sloot - son of a wealthy Dutch judge - is currently being held at Miguel Castro Castro Jail in Peru where he awaits the murder trial for the death and robbery of Stephany Flores in June 2010.
It is believed that his girlfriend - who has not been identified - has been visiting the 23-year-old frequently for conjugal visits at the jail, going to his cell to do 'chores' and bringing him candy.
According to the Atlanta Journal Constitution, van der Sloot uses the candy to run a 'lucrative' snack bar from his cell.
It is also believed that the girl worked at the casino which Stefany Flores was in the night van der Sloot allegedly murdered her by strangling and suffocating her.
He has admitted to the murder but has pleaded 'violent emotion' - which is typically used in Peru for crimes of passion.
The victim’s father, Ricardo Flores, saw van der Sloot at a recent court hearing and said he expected to see a 'miserable person' but instead was was shocked to see a 'fatso'.
He has asked jail officials to investigate the conjugal visits.
It recently emerged that the 23-year-old was so desperate for money he allegedly told a friend he was going to work on the streets.
The National Enquirer said van der Sloot made the claims in a 44-minute exchange of emails between himself and a friend.
He told the friend he had unsuccessfully asked his wealthy family for a lend of money but they refused because they thought he would spend it on gambling.
Van der Sloot could spend just 20 months in jail if a judge accepts his defence of 'violent emotion'.
He is currently accused of first-degree murder, and faces a 15- to 35-year sentence if his plea is not accepted. Read More