His best friend, Peter Clifford, was best man at the couple's Kiev wedding and, giving evidence at the inquest at Devon County Hall on Tuesday, said Mr Pring was "totally under her influence".
He said: "There is no reasonable doubt in my mind that Barry was murdered, nor is there any reasonable doubt in my mind that Ganna Ziuzina either arranged for, or was complicit in, his murder."
Coroner, Dr Elizabeth Earland said that "strenuous" - but ultimately unsuccessful - attempts had been made to try to get Ms Ziuzina to attend the hearing.
She read out a statement given by Ms Ziuzina who said she had given three separate statements to police in Ukraine and did not "believe I can add anything further".
Mr Pring's brother, Shaughan, said he believed Ms Ziuzina was "only interested in Barry for his money and saw their relationship as an opportunity to better her position financially".
He added that his brother was "besotted" by the woman, who he knew as Anna, but that she "became very demanding", asking for money.
The inquest heard Mr Pring, originally from East Devon, set up his own consultancy business aged 30 after moving to the London area and that his career required him to travel extensively.
His mother, Irene, said in a statement that her son started seeing Ms Ziuzina, who he said was a teacher, when he was 46.
Mrs Pring said her son frequently flew to Kiev and started supporting Ms Ziuzina financially after she stopped working as a stripper.
In early January 2007 Mr Pring told his parents to expect an announcement and then phoned on January 23 to say he would be marrying four days later.
"No one from our family was invited," said Mrs Pring. "Barry returned to live in London. Anna stayed in Kiev, moving to the apartment that Barry had bought ... we all expected her to get her visa straight away."
Mrs Pring said of the visit: "I was quite surprised to see how cold she was towards Barry.
"She was not loving or caring towards him at all. She never lifted a finger [or did] anything. She was a lazy thing ... she was not providing a home for my son."
The court heard Mr Pring, who owned a total of five properties including three in the London area, bought another apartment in Kiev and sent Ms Ziuzina £40,000 to finish it.
She spent that Christmas with Mr Pring in Devon before flying back to Ukraine again, his mother said.
Mrs Pring heard about her son's death when his brother, Shaughan, came to tell her that Ms Ziuzina had phoned to report that he had been killed.
She said the family became suspicious and hired a private investigator in Ukraine, spending £100,000 in an attempt to find the truth.
"We are sure that Anna had some involvement in Barry's death in order to inherit money or property," she added.
"Our family has lost a treasured son, brother and uncle which will have an affect on us all for the rest of our lives."
The inquest heard how after Mr Pring's death, Ms Ziuzina travelled to London, sold her husband's Range Rover and the contents of his apartment and removed money from his British bank account.
Dr Gyan Fernando, then a Home Office pathologist, examined Mr Pring's body after it was returned to the UK from Ukraine.
The inquest heard that blood tests revealed alcohol in Mr Pring's blood at the time of his death, which indicated that he was likely to have been intoxicated to some degree.
The case was investigated as an unexplained road traffic accident but police in the Ukraine upgraded their inquiry to a murder hunt in 2011.
The hearing continues.