An Australian Salvation Army officer, attacked in Malawi while on a private preaching tour, has died.

Western Australian Major Geoff Freind was placed in an induced coma in a Johannesburg hospital following the attack but died on Wednesday.

On leave from his job in Perth, the 59-year-old grandfather was on a five week solo preaching tour in Africa - having previously visited Rwanda - when he was attacked in Malawi walking from shops to his hotel.

His wife Lyn and four sons had travelled to be by his side. Major Freind's brother-in-law Peter Walker told the ABC the family was devastated by his death, saying his family was the "centre of his life".

In a statement The Salvation Army expressed its "heartfelt and sincere condolences" to the family and said Major Freind's death will be "felt right throughout The Salvation Army internationally as well as those who have been impacted by his local ministry in Western Australia".

"Whether it was through his books sharing the challenges of life’s journey, through his personal relationships developed through his ‘Hotel Ministry’ or keen interest in coaching and supporting local sporting teams, Geoff simply loved engaging with people. For 34 years, Geoff has served the community as a Salvation Army Officer and given his best."