The banned Jamaat-ud-Dawah (JuD) head, who carries a USD 10 million American bounty on his head for terror activities, walked free on Friday after the Pakistan government decided against detaining him further in any other case. He was under house arrest since January this year.
Lahore-based law firm - Mirza and Mirza Law Associates - has filed the petition on behalf of Saeed in the UN.
Supreme Court Advocate Navid Rasul Mirza, the owner of this law firm, told PTI today that his law firm had recently filed the petition in the UN.
"My law firm has filed the petition on Hafiz Saeed's behalf at the UN seeking removal of his name from its list of designated terrorists. My son Haider Rasul who is director of this firm is looking after this case," he said.
Saeed, who is accused of having masterminded the November 2008 Mumbai attack that killed 166 people, was placed on the terrorism black list by the United Nations under UN Security Council Resolution 1267 in December 2008.
To a question about any progress in the case so far, Mr Mirza said: "We have just filed the petition."
Mr Mirza was Additional Advocate General of Punjab Government (1993-1996) and Prosecutor General for the National Accountability Bureau, a government anti-graft body (2000-03).
This is the first time that Saeed has hired a law firm other than that of his permanent counsel Advocate AK Dogar.
"In Pakistan, all cases of the JuD chief are being handled by Dogar. This firm to pursue his case in the UN has been hired in consultation with Dogar," a Jamaat-ud-Dawah office-bearer told PTI.
The office-bearer said Saeed has decided to challenge the UN's decision on the basis of different court decisions since 2009 in which no allegation - either related to terrorism or otherwise - has been proved in the Pakistani courts.
He said the UN's decision to place Saeed's name on the list of terrorists had caused harm to his reputation as it appeared that this had been done on international pressure.
LeT operations commander Zakiur Rehman Lakhvi was also placed on the terrorism black list along with Saeed.
According to the UNSC's sanctions committee, the LeT leaders were "subject to the assets freeze, travel ban and arms embargo," set out in Security Council resolution 1822.
The UNSC website says: "Saeed is proscribed for being associated with Lashkar-e-Taiba and Al-Qaeda for participating in the financing, planning, facilitating, preparing or perpetrating of acts of activities by, in conjunction with, under the name of, on behalf or in support of both entities."
India has repeatedly asked Pakistan to re-investigate the Mumbai terror attack case and also demanded trial of Saeed and Lakhvi in the light of evidence it had provided to Islamabad.
A Lahore High Court's Judicial Review Board last week unanimously ordered Saeed's release after the Punjab government failed to provide any evidence related to terrorism or otherwise before it.
After his release, Saeed said the US, on India's request, pressured Pakistan to detain him. "I was detained on the pressure of the US on the Pakistani government. The US did so on the request of India," he claimed.
India had expressed outrage over the decision of the judicial board to release Saeed, calling it an attempt by Pakistan to mainstream proscribed terrorists and a reflection of its continuing support to non-state actors.
The JuD is believed to be the front organisation for the banned LeT which is responsible for carrying out the Mumbai terror attack in 2008.
Saeed was put under house arrest after the Mumbai attack in November 2008 but he was freed by a court in 2009.
Nine of the Mumbai attackers were killed by police while lone survivor Ajmal Kasab was caught and executed after a trial.