OTTAWA (AFP) - A traveller who returned to Canada from Liberia with symptoms that initially triggered fears of the spread of the deadly Ebola virus was pronounced clear of the disease on Tuesday.

"I can confirm to you that the test was negative," Mr Michael Bolkenius, spokesman for Canadian Health Minister Rona Ambrose, told AFP.

The World Health Organization, meanwhile, said tests on the man for the Marburg virus, Lassa fever, Crimean-Congo haemorrhagic fever and Rift Valley fever had also proved negative.

The man had been placed in quarantine pending the results of tests by the National Microbiology Laboratory in Winnipeg, Manitoba. His family were also placed in quarantine in Saskatchewan province, according to provincial health officials.

The man had been in Liberia but developed the symptoms after landing in Canada.

Aid workers and health officials in Guinea are battling to contain west Africa's first outbreak of the deadly Ebola virus, after neighboring Liberia reported its first suspected victims.

At least 59 people are known to have died in Guinea's southern forests but the Liberian cases, if confirmed, would mark the first spread of the highly contagious pathogen between the countries.

Ebola is one of the world's most virulent diseases.

It is transmitted to humans from wild animals and between humans by direct contact with blood, feces or sweat, or by sexual contact and the unprotected handling of contaminated corpses.