A senator belonging to ousted prime minister Imran Khan's Pakistan Tehreek-e-Insaf (PTI) party has been granted bail by a local court in a case about his controversial tweet against Army chief General Qamar Javed Bajwa.

Senator Azam Swati was arrested more than a week ago by the Federal Investigation Agency (FIA) following his tweet against Gen Bajwa after a court released Prime Minister Shehbaz Sharif and his son in an alleged money laundering case involving Rs 16 billion.

A district and sessions court in Islamabad on Friday granted post-arrest bail against a surety bond worth Rs 1 million to Swati, the Express Tribune newspaper reported.

Special Judge Central Raja Asif Mehmood announced the verdict on Friday which was reserved a day earlier.

At the previous hearing, special prosecutor Raja Rizwan Abbasi raised objections at the court's jurisdiction and said this case should be transferred to the session court.

The prosecutor argued that the accused had given a hateful statement about the head of a state institution through his tweet.

"The institution had no connection with the courts' decisions, he said, adding that the accused had used a provocative way against state institutions at a public forum. Swati had also admitted to it during the investigation," Abbasi said.

In his concluding arguments, Swati's counsel Baber Awan said that his client had used the right of freedom of expression through his tweet. My client was tortured and humiliated during the custody, he alleged.

Swati was taken into custody by the FIA's Cybercrime Wing (CCW) from his home in Islamabad on October 13 after registering a case against him over the tweets.

Mr Bajwa congratulations to you and few with you. Your plan is really working and all criminals are getting free at the cost of this country, he had tweeted after the acquittal of Prime Minister Sharif and his son Hamza Shehbaz.

Swati went on to add: With these thugs getting free you have legitimised corruption. How you predict now the future of this country? PTI SH ZH