A massive leak – dubbed the "Panama Papers" – has revealed questionable offshore holdings of 140 politicians and public officials from around the world, including a number of prominent Arab leaders.

The leak was revealed after a yearlong investigation by the International Consortium of Investigative Journalists, German newspaper Süddeutsche Zeitung and more than 100 other news organizations.

Officials from the United Kingdom, Iceland, Argentina and many other countries are included in the leak, along with current and former leaders of Iraq, Saudi Arabia, Qatar, Palestine, Algeria, the United Arab Emirates and Sudan. Prominent relatives and associates of Arab leaders, including cousins of Syrian President Bashar Assad, the son of former Egyptian President Hosni Mubarak and the personal secretary to the king of Morocco, also had account details leaked.

"The cache of 11.5 million records shows how a global industry of law firms and big banks sells financial secrecy to politicians, fraudsters and drug traffickers as well as billionaires, celebrities and sports stars," the ICIJ said in its report Sunday.

However, while offshore accounts are often associated with corruption and illegal activities, the report points out that "most of the services the offshore industry provides are legal if used by the law abiding."

While many European leaders named in the leak are being accused of tax evasion – the lack of taxes in many Gulf states and the royal status of some of the Arab leaders named make it unlikely that there will be the same repercussions in the Arab world.

Mossack Fonseca, the Panamanian firm involved with the offshore transfers, said "that it conducts periodic follow-ups in the case of politically-exposed figures to assure that no negative results are found. The company said that for 40 years it has operated beyond reproach in its home country and in other jurisdictions where it has operations," according the ICIJ.

"Our firm has never been accused or charged in connection with criminal wrongdoing," a public relations officer for the firm said.

Here are the Arab leaders included in the leak:

Former Prime Minister Ayad Allawi, Iraq

Former Prime Minister Ali Abu al-Ragheb, Jordan

Former Prime Minister Hamad bin Jassim bin Jaber Al Thani, Qatar

Former Emir Hamad bin Khalifa Al Thani, Qatar

King Salman, Saudi Arabia

Crown Prince Mohammad bin Naif, Saudi Arabia

President Ahmad Ali al-Mirghani, Sudan

President Khalifa bin Zayed, UAE

Minister of Industry and Mines Abdeslam Bouchouareb, Algeria

Former Deputy Prime Minister and Minister of National Economy Mohammad Mustafa, Palestine