Saudi Arabia's Crown Prince Mohammed bin Salman has "ordered the immediate release" during his high-profile visit to Islamabad.
In a post on Twitter, Pakistan's Information Minister Fawad Chaudhry said the crown prince took the call following a request by Pakistani Prime Minister Imran Khan.
Prince Mohammed is in Pakistan at the beginning of an Asian tour, which will include India and China.
This comes as Saudi Arabia on Sunday signed investment agreements with Pakistan worth $20 billion.
Saudi Arabia has yet to comment on the Pakistani announcement of a prisoner release.

US and Iran signal a peace deal is close
Qatar rejects media report on energy production decisions
Trump says Iran war deal close as Strait of Hormuz tensions linger
Victims' families mark Air India crash anniversary with prayers and tributes
Ebola outbreak spreads to crowded displacement camp in Congo
Fire breaks out at New Zealand's Wellington airport, disrupting flights
Ukraine and Russia trade overnight drone strikes, officials say
UN says Taliban arrest 30 women for violating hijab rules in Afghanistan
