Relatives of former British soldier Simon Mann have spoken of their delight after he was granted a full pardon for his part in a failed coup plot in Equatorial Guinea.

Mann, 57, was sentenced to a 34-year jail term after admitting conspiring to oust President Teodoro Obiang Nguema Mbasogo, leader of the tiny West African country.

A statement released by the Mann family read: "The family is absolutely delighted that Simon has been pardoned and is to be released shortly."

Mann was granted the full pardon on humanitarian grounds, a statement on the website of Equatorial Guinea's Information Ministry said.

The mercenary has been held in the country's notorious Black Beach prison and is expected to be released later on Tuesday. He will then be free to return to the UK. A family spokesman said Mann was due to arrive home "in the next few days".

A Foreign Office spokeswoman said: "We have been informed of the imminent release of Simon Mann. We understand this was a personal decision by the President of Equatorial Guinea on humanitarian grounds."

Mann was sentenced in July last year following a high-profile trial. The former SAS officer was accused of masterminding an operation to oust President Obiang.

The old Etonian was originally arrested with around 70 other people, mostly former soldiers, when their aircraft arrived at an airport in the Zimbabwean capital, Harare, in March 2004. The plan was to put opposition leader Severo Moto, who is exiled in Madrid, in power and gain control over the country's oil wealth.

At first Mann denied that the group had come to collect weapons for a coup. His lawyers claimed they were on their way to the Democratic Republic of Congo to help secure diamond mines. He was jailed for seven years in Zimbabwe for conspiring to buy weapons of war.

Mann said he suffered a violent abduction in February from Chikrubi prison in Zimbabwe to Equatorial Guinea. He has always insisted that he was not the main man behind the plot.