Afridi, who has apologised for the 'spot-fixing' scandal involving Pakistani players that has shaken the core of international cricket, said Hameed cannot be trusted.
"Yasir Hameed is about 30 or 31 - but mentally he is 15 or 16," Afridi said.
"People know the type of character he is. We have known him for a long time and we know what to expect from him. He has done this sort of thing many times. Is he unreliable? Well, he is sitting with someone he does not know and gives these messages out, so, yes.
"I don't know who he was sitting with or in what situation he gave this message," he added.
In the video of a sting operation carried out by the 'News of the World', Hameed had claimed that almost every match Pakistan played was fixed. But he later went back on the statement, saying that he was tricked and later blackmailed to stand by the remarks.
Afridi, who led Pakistan in yesterday's Twenty20 match against England which the visitors lost, said he has told his players not to read newspapers.
"It was a relief to be playing again. Even though it was not a perfect performance. All the allegations are history now and until the ICC completes their investigations and it is all before us, we don't want to talk about it," he said.