Spurs are signing Fryers from Standard Liege after the youngster left United in the summer.
"I am disappointed in Tottenham," said Ferguson.
"It is a blatant manipulation of the situation. They tried to buy him from us at the end of last season but we couldn't agree terms. Then they took him on trial, came back from Portugal and said they couldn't afford him.
"The league should look into it. They should stop the registration until they examine it. There will be a trail. Either mobile phones or something. It is obvious to me."