A group of defectors fighting for the M23 rebel movement against the Congolese army say that they were recruited and trained in neighbouring Rwanda against their will.

The revelations come after weeks of fighting in the east of the country and would be the first direct evidence that Rwandan troops are involved in the fighting that has displaced thousands from their homes.

The allegations made by the rebel defectors across the border in Congo will strain relations with Rwanda, but so far officials from both sides have held back, and are talking about a joint investigation to get to the bottom of the matter.

Al Jazeera's Malcolm Webb reports from Kigali.