The Democratic Republic of Congo's wanted opposition leader plans to go to Portugal for medical treatment, a South African diplomat says.
Mr Bemba says he was not planning a rebellion
Jean-Pierre Bemba took refuge at the South African embassy in the capital, Kinshasa, after clashes between his militia and the army last week.
The fighting threatened to derail the peace process that led to recent polls.
A BBC correspondent says there is speculation the trip may be used as a diplomatic manoeuvre to ease tension.
President Joseph Kabila defeated Mr Bemba, a former rebel leader, in a second round run-off vote last October.
Mr Bemba denied plotting military action to overthrow the president and accused the army of trying to kill him.
The violence started when his armed bodyguards refused to be integrated into the national army before last week's deadline.
Up to 600 people may have died in the clashes, according to EU diplomats in Kinshasa.
South Africa's UN ambassador said Mr Bemba was "not a refugee" in the South Africa diplomatic compound in Kinshasa.
"Mr Bemba is planning to leave on Saturday to go to Portugal where he has been receiving medical treatment for a broken leg," Dumisani Kumalo told the BBC.
As a senator, Mr Bemba, who has been charged with treason, enjoys immunity from prosecution. The government says it will seek to have this stripped.
The BBC's Arnaud Zajtman in Kinshasa says Mr Bemba spent several weeks in Portugal after the election seeking medical treatment for his leg.
Mr Kabila has said that no-one can be above the law.
But the trip looks like a diplomatic way to get round the issue of Congolese justice, our correspondent says.
Observers doubt that Mr Bemba would return to DR Congo to face trial if he got permission to go to Portugal for treatment.
A meeting of the southern African leaders in Tanzania is expected to discuss the violence.
Earlier, the United States condemned it says it represented "a set-back in the progress the Congolese people expect and deserve after last year's historic election."