The deputy leader of Uganda's rebel Lord's Resistance Army is missing, feared dead, after reports of a falling out with LRA leader Joseph Kony.
Vincent Otti is wanted by The Hague for war crimes
A spokesman for the Ugandan Peoples' Defence Forces, Lt Chris Magezi, told the BBC that Vincent Otti, his wife and children were killed weeks ago.
He is one of four LRA leaders indicted by the International Criminal Court.
The LRA were notorious for mutilating victims and kidnapping children to be fighters, porters and sex slaves.
Officials in southern Sudan usually in close contact with Mr Otti confirm they have not had any recent communication and for a month he has failed to get in touch with Ugandan FM radio stations that he usually contacted regularly.
Security sources quoted in the state-owned New Vision newspaper say Okot Odhiambo has been appointed as LRA deputy.
Ugandan military sources say they have intercepted satellite telephone calls made by Mr Kony, indicating that his men had killed Mr Otti in a power struggle within the LRA.
Asked by the BBC's Focus on Africa if the Ugandan government and army could be "planting stories to make it seem that the LRA was in disarray", Lt Magezi said this was "not in their interest" and they were "focussed on the peace talks".
And he insisted that the army had "reasonable grounds" to believe the reports of Mr Otti's death.
But an LRA spokesman visiting Uganda, Martin Ojul, denied rumours of a split in the leadership and said Mr Otti has been suffering from cholera.
Mr Ojul is currently leading an LRA delegation in an unprecedented six-week authorised visit to northern Uganda, including visiting refugee camps, to meet some of the victims of the 20-year insurgency.
The delegation received a warm welcome at Camp Kochgama in Amuria where Mr Ojul addressed the refugees in Acholi to ask for their forgiveness and for their support in rejecting the ICC warrants in favour of Ugandan justice.
The BBC's Sarah Grainger who accompanied them to Camp Kochgama says that there was a unanimous show of hands in favour of forgiving the LRA.
Our reporter says that people "just want peace to return".
After their six-week visit to Uganda, the LRA delegation will return to peace talks mediated by the Sudan Peoples' Liberation Movement (SPLM) government in southern Sudan.
The SPLM have told the French news agency, AFP, that they too have been unable to establish contact with Mr Otti, who was the key liaison figure between themselves and the LRA leader.
The LRA says this is only because Mr Otti's telephone has been changed to evade surveillance by the Ugandan army (UPDF).
However, the UPDF Fourth Brigade says it has obtained information from the LRA base camp in Garamba in north-eastern Democratic Republic of Congo that Mr Otti was executed by firing squad, along with three others, about three weeks ago.
The state-owned New Vision newspaper says it has obtained an intelligence brief which says "Otti was killed on or around 8 October 2007 during a high command meeting that Kony convened at his base camp in Garamba".
"Kony also feared that Otti was dealing with individuals who wanted to eliminate him and take over the leadership," the newspaper adds.