(WASHINGTON) -- An American-born jihadist fighting for an al Qaeda affiliate in Somalia, who was featured in a recent ABC News report, has allegedly been killed by the terror group, months after a public spat between the Alabama-raised man and the group's leadership.
Omar Hammami, known in the terrorist organization of al-Shabaab as Abu Mansoor al-Amriki, has been reported dead several times before, but an African diplomat in the region and an American terrorism expert, who has been in contact with Hammami told ABC News the reports are very likely true this time. An FBI official said so far the information is unconfirmed.
Hammami is one of the highest-profile members of al-Shabaab and one of the most prominent accused American terrorists, with a $5 million reward from the State Department for information leading to his capture.
Hammami's father, Shafik, said on Thursday that he had been told of the reports but had no way to know if his son was actually dead.
"Of course I hope not, I hope it's not true," Shafik Hammami told ABC News in a telephone interview from his Alabama home. "Our lives have been on a roller coaster for a long time, and we've been there before...we just hope that it's not true this time."
If the reports are accurate, however, Shafik said his son died "fighting for his principles."
"He did what he wanted to do and he fulfilled his principles," Shafik said. "If he indeed died, he died fighting for his principles, whatever they are."
Omar was sometimes referred to as the rapping jihadist after he produced several videos of him rhyming about waging war on the West and the glory of martyrdom.
His mother, Debra, told ABC News last May that she didn't "agree with the ideology of any of that."
"But I do love my son and I do have motherly love," she said then. "If I could just touch him for five minutes, I would be thrilled."
Omar, who was active on Twitter, suddenly disappeared from the social networking site months ago, following what he said were al-Shabaab assassination attempts. Omar and the local al-Shabaab leadership had an oddly public falling out, culminating in Omar posting videos online in which he said he feared for his life.
When he stopped tweeting, many observers speculated that Omar had been killed then, but American intelligence officials told ABC News in mid-August that Omar was still alive.
Author and terror expert J.M. Berger, who has interacted with Omar since he surfaced on Twitter this year and monitors Shabaab social networks, said that unlike past reports of his death, this time it seems likely to have happened.
"The evidence strongly points to this report being true compared to previous claims, which were weakly sourced. The sources in this case include people known to be close to Hammami," said Berger, a writer and analyst for IntelWire.
An African diplomat in the region told ABC News there is a "significant possibility" Omar is dead, but final confirmation won't come without DNA tests.
A spokesperson for the U.S. State Department and a self-described representative for al-Shabaab have not immediately returned request for comment.
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