The 23-year-old man, who lives in the city, is due to appear at Hull Magistrates Court today.
Another man, aged 28, was arrested on Tuesday as part of the investigation and he remains in police custody this morning.
A 42-year-old woman, who was arrested earlier this week, has been released on conditional bail, while an 18-year-old woman who had also been arrested has been released without charge.
The body of Mr Poskus was found in a grassed area at Danepark Road, in the Orchard Park area of the city, on Friday night. He was from Lithuania and had been living in Hull.
Detectives have also renewed an appeal to trace two people who were seen in the area and could have information useful to their investigation.
Detective Inspector Chris Calvert, from the Major Crime Team, said: "This is an ongoing investigation and we are continuing enquiries.
"We made an appeal yesterday to trace a man and woman who were seen walking down Arthur Street in the early hours of Wednesday, June 13. We are reiterating that appeal today as follows.
"We are keen to speak to these people as they may have some information that could assist our investigation.
"The first was a woman with long dark hair who was carrying a shopping bag. She walked down the street at around 1.30am.
"Shortly after this, a man walked a black and white dog down the street. He was wearing black trousers and a light coloured top.
"If this was you please call 101, quoting log 523 of 15 June 2018."