The men, aged 20 and 21, are said to have confessed to knifing Anna Lightfoot, 27, to death for just a few pounds. They could face the death penalty.
Ms Lightfoot, of Saddleworth, near Oldham, Greater Manchester, was killed on 24 August during an expedition to help organise young volunteers on a Raleigh International project in the former British colony in Central America.
Tim Stew, deputy British High Commissioner, said one of the men was also expected to be charged with a rape offence unconnected with the murder of Ms Lightfoot. "Both men have admitted to robbing and killing Anna. They didn't take a lot, just a small amount of money. There was no sexual motive."
The results of a second post- mortem examination yesterday confirmed Ms Lightfoot died of stab wounds, and that there was no evidence of sexual attack.
Raleigh International said all its volunteers in the country would be remaining to take part in other projects.Reuse content