The charges include involvement in genocide and gross violation of the Geneva Convention.
The Jamaat, an ally of the country's leading opposition Bangladesh Nationalist Party (BNP), was earlier de-registered as a political party by the Election Commission (EC) in August 2013.
The Commission said the party’s charter was incompatible with the Bangladesh constitution.
On Tuesday, Abdul Hannan Khan, the coordinator of ICT's investigating agency, said the 373-page report detailing Jamaat’s role in 1971 war was finalised after a probe lasting seven months.
The report would be handed over to the prosecution, Khan told a media briefing.
The two war crimes tribunals of Bangladesh have been trying the top leadership of the party since 2010 and several of them have already been sentenced to death or for life.
It is during the trials of its senior leaders on war crimes charges that the anti-liberation role of Jamaat became evident, prompting the tribunal’s investigators to probe charges of war crimes against the party and its affiliates.
The first war crimes tribunal described Jamaat as a ‘criminal organisation’ in its verdict sentencing its top war-time leader Ghulam Azam to 90 years in prison.
The tribunal made similar observations while handing down death sentences to other Jamaat leaders like Delwar Hossain Sayedee, Abdul Quader Molla and Muhammad Kamaruzzaman.
Khan said they have found evidence of involvement of Jamaat and its affiliates in genocide, violation of the Geneva Convention and the International Law, attempt to commit crimes against humanity and conspiracy.
The investigators have provided 70 witnesses in its report.
The report said that Jamaat and its affiliates -- Islami Chhatra Shangha, the ‘Shanti Committee, Razakar, Al Badr and Al Shams -- aided the Pakistan Army and committed serious crimes punishable under the 4 (1) and 4 (2) of the International Crimes Law.
“The policy, policymakers and members of these organisations are responsible for these crimes,” reads the report.
Altogether 2,303 pages of documents in seven volumes have been attached to the probe report. Ten more volumes of additional documents, earlier verdicts from the ICT and its observations of Jamaat are also being added.
"Jamaat-e-Islami was banned four times. This organisation and its associates are responsible for the turmoil in Bangladesh. We will ask for a permanent ban on them,” said Khan.
He also said a plea to confiscate property owned by Jamaat affiliates will be made.
“The organisation might be banned or have their properties confiscated,” prosecutor Tureen Afroz told bdnews24.com.
“The trial will be held in absentia if there is no defendant.”
The recent demand for a complete ban on Jamaat first came from the movement of the secular platform, Ganajagaran Mancha, which launched a mass movement in February last year demanding death penalty for 'war criminals' of 1971.
The movement led to an amendment of the law for trial of war crimes, which made it possible to try an entire political party for it, not just individuals.
The tribunals have pulled up the Jamaat for being an auxiliary force of the Pakistan army's brutal campaign to crush the liberation struggle.
The judges have observed during trials of its leaders that there is no evidence that the Jamaat has reversed its view on the 1971 Liberation War.
The Pakistan National Assembly passed a resolution condemning the execution of Jamaat leader Abdul Quader Molla last year, saying he was punished for his 'loyalty to Pakistan'.
Even cricketer Imran Khan drew huge flak from Bangladeshis for condemning the hanging of the Jamaat leader.
In an apparent effort to counter the huge backlash and save its leaders from the gallows, Jamaat activists resorted to large-scale violence last year.
They also ganged up with the BNP to stop the parliament elections.
Scores of Jamaat activists are now facing charges of murder, sabotage and arson during the violent campaign, especially for attacking police and security forces.
After the controversial Jan 5 parliament polls, security forces launched operations in areas dominated by the Jamaat and its affiliates.
On Mar 25, on the eve of Bangladesh Independence Day, Prime Minister Sheikh Hasina called for 'eternal vigil' against the forces that opposed the country's independence.
“The conspiracy to undermine our sovereignty continues and we must guard our hard-earned independence with all we have," she said.
On the night of Mar 25-26 in 1971, Pakistani troops cracked down on the unarmed Bengalis and unleashed a campaign of murder, rape, arson and pillage.
Tens of thousands died during Pakistan's 'Operation Searchlight" that led to Bangladesh's emergence as a sovereign nation with Indian support.
When the Awami League, which had spearheaded the fight for independence, returned to power in 2009, it set up the war crimes tribunals to prosecute those responsible for heinous crimes during the Liberation War.
The Jamaat has rubbished these trials and alleged that they were part of a state-sponsored vendetta against the party.