Wanyama's current deal with the Scottish champions lasts until 2015, but Celtic were keen to tie him to a new contract to fend off interest from several English Premier League clubs including Manchester United.
However, the 21-year-old, who joined Celtic from Belgian side Beerschot in 2011, doesn't believe the Hoops' offer reflects his value and he has rejected the deal.
Wanyama's agent Rob Moore told STV: "Victor has informed Celtic the contract offer fell short of his expectations.
"There were a number of aspects that fell short - he turned it down."
Celtic reportedly turned down an offer for Wanyama from an unnamed club in the close-season and, while Moore insists his client remains happy at Parkhead, he believes the Nairobi-born star deserved to be rewarded with a significantly improved contract for staying committed to Neil Lennon's team.
"He is very happy with the job he is doing at the moment. He is a great professional and his commitment cannot be questioned," Moore added.
"But it doesn't take a rocket scientist to work out that he lost great earning potential in the summer (by not moving to England)."
Source: AFP
Source: AFP