Former prime minister and veteran PPP leader Yousuf Raza Gilani on Wednesday sent a legal notice to Pakistan-based American blogger Cynthia Ritchie, asking for an apology and withdrawal of the "false" and "frivolous" allegation that he "physically manhandled" her.

The development was revealed by the former premier's sons — Ali Haider and Kasim — on Twitter.

"My father Syed Yousuf Raza Gilani through his lawyer has sent a legal notice of defamation to Cynthia D. Ritchie which she will soon receive. The libel will cost her Rs100 million if she fails to prove otherwise," Ali wrote.

The legal notice, a copy of which was shared by Kasim on his Twitter account, accuses Ritchie of levelling a "false, frivolous, baseless and vexatious" allegation against the former prime minister.

The notice says that Gilani is "considered a role model and followed by a great number of persons around the world", adding that he has great respect for women and has "always spoke[n] for their rights".

"The wording used by you (Ritchie) clearly falls within the ambit and purview of libel," it says, adding that due to her allegation, "the honesty, righteousness, culpability and credibility" of Gilani was "questioned".

Gilani, through the notice, has demanded from Ritchie Rs100m in damages, along with an apology and court and attorney's fees.

"Any further publication/communication/circulation of these defamatory allegations will only expose you (Ritchie) to greater legal penalties," the notice sent through his lawyer says.

Ritchie had last week accused Gilani of "physically manhandling" her while he was staying at the "President's House".

Soon after, the former prime minister had denied the allegations in a statement and later said he would file a defamation suit against the blogger, claiming she had "violated [his] respect by making such unfounded allegations".

Talking to ARY News last week, he had questioned as to what Richie was doing at the President's House when she was allegedly manhandled, and why she had been staying in Pakistan. He had alleged that she had come to Pakistan as part of a campaign to malign politicians.

The PPP leader had also claimed that Ritchie was maligning him because his two sons had filed a defamation case against her for her allegedly defamatory tweet against former prime minister Benazir Bhutto.

According to Gilani, he had "never even met" Ritchie when he was the premier.

"If she was part of a delegation I don't know but my only meeting with her was in 2019 at a diplomat's house in Islamabad. Jalil Abbas Gilani and other party leaders were also present during that meeting," he had said.

Ritchie, who was at the centre of a controversy last month when she tweeted what the PPP described as "derogatory and slanderous remarks" about Bhutto, had also accused PPP Senator Rehman Malik of raping her in a live video posted on her Facebook page.

Malik has since sent two legal notices to the blogger through his lawyer, asking for a public apology and withdrawal of rape allegations within 15 days.