Kaneria, only the second Hindu to play for Pakistan after his maternal uncle Anil Dalpat, took 261 wickets in 61 Tests at an average of 34.79. He also played 18 ODIs.
Akhtar made the revelation during a show 'Game on Hai' aired on PTV Sports.
"In my career I fought with two three (in the team) when they started talking on regionalism. Things like 'who is from Karachi, Punjab or Peshawar', that used to infuriate. So what if someone is a Hindu, he is doing well for the team.
"They used to say 'sir ye yaaha se khaana kaise le raha hain' (how is he taking food from this place)?" said the 44-year-old, who played 46 Tests and 163 ODIs.
"The same Hindu won the Test for us against England. If he is taking a bagful of wickets for Pakistan, he should play. We could not have won the series without Kaneria's effort. But not many gave him credit for that," said Akhtar.
When contacted, Kaneria supported Akhtar's claims.
"Shoaib has been a legend of the game. His words are also as blunt as his bowling. When I was playing I did not have the courage to speak on these matters but after Shoaib bhai's comments, I do. He has always supported me and also Inzy bhai (Inzaman-ul-Haq), Mohammad Yusuf and Younis bhai (Younish bhai)," Kaneria told PTI over phone from Karachi.
"Those who did not support me, I will make their names public soon. Having said that, I feel fortunate and honoured that I got to play for Pakistan," added Kaneria.
Kaneria, now 39, was found guilty of spot-fixing alongside Mervyn Westfield while playing for Essex against Durham in 2009.
The leg-spinner was found to have convinced Westfield to concede 12 runs during the one-day game. Westfield was handed a four-month prison sentence and ECB banned him for five years.
Kaneria admitted to spot-fixing in 2018 after six years of denial.