Senior al-Qa'ida figure Majid al-Majid dies in custody in Lebanon

An army statement said al-Majid died in a military hospital in Beirut

Majid al-Majid was the alleged leader of the group that claimed responsibility for the attack on the Iranian embassy in Beirut in November (AP)

Majid al-Majid, the leader of an al-Qa'ida-linked group in Lebanon who claimed responsibility for attacks across the Middle East has died in custody, the Lebanese army has said.

In a short statement, it said al-Majid, who was on Saudi Arabia's most-wanted terrorist lists, “died this morning while undergoing treatment at the central military hospital after his health deteriorated.”

It did not provide any further details, other than that he had been receiving treatment at a military hospital in Beirut.

Earlier, a Lebanese army general speaking on condition of anonymity told The Associated Press that al-Majid died after suffering kidney failure. This was not verified by the state-run National News Agency, who said al-Majid died “after his health conditions deteriorated.”

Al-Majid, a Saudi citizen, was detained in Lebanon late last month and was being held at a secret location.

He was the purported commander of the Abdullah Azzam Brigades, a Sunni militant group with al-Qa'ida links. The group recently claimed responsibility for an attack on Iran's Beirut embassy in November which left 23 people dead and wounded dozens.

The Brigades have also claimed responsibility for other attacks throughout the region, including the 2010 bombing of a Japanese oil tanker in the Persian Gulf and several rocket strikes from Lebanon into Israel.

The US State Department declared his group a foreign terrorist organization in 2012, freezing any assets it holds in the United States and banning Americans from conducting any business with the group.

Reports of his arrest began to surface in Lebanon earlier this week. Security officials eventually confirmed that they had a suspect in custody, but at the time said they were not certain of his identity.

His identity was confirmed by authorities on Friday following a DNA test.

Al-Majid was believed to have serious kidney problems requiring dialysis. He was an important figure, and the Abdullah Azzam Brigades grew from a relatively small outfit to a larger terror group since he took over in mid-2012, after the organization's previous leader, Saleh al-Qarawi, was gravely wounded in Pakistan.

According to Lebanese newspapers, al-Majid was detained during the last week of December while on his way from Beirut to the eastern Bekaa Valley that borders Syria. The reports said that he was captured while in an ambulance after he had undergone dialysis at a hospital in Beirut.

In the spring of 2013, after the Lebanese Shiite Hezbollah group announced that it was fighting alongside Syrian President Bashar Assad's troops against the Syrian rebels, the Abdullah Azzam Brigades began to target Hezbollah as well — and by extension, their Iranian patrons.

On Friday, families of those killed in the Iranian embassy bombing demanded that al-Majid, who had not been charged in the attack, be tried in Lebanon and not be sent to his homeland.

Additional reporting by Associated Press