The president of Zimbabwe, Mr Robert Mugabe, flew to Singapore last week to undergo secret tests for prostate cancer, the Times Of London has reported.
The newspaper said that he had flown to Singapore because that kind of medical treatment was no longer available in his run-down hospitals in Zimbabwe.
His departure for Singapore, said the paper, has left loyalists in his ruling party wondering who was in charge of the country - with just a month to go before a run-off in the presidential election.
The Times report quoted sources close to the government as saying that the 84-year-old president travelled to Singapore on Wednesday. He was due to return home on Sunday but there was no confirmation of this.
These sources said the tests were being conducted by a Malaysian urologist who was also known to have provided "certain financial services" for Mr Mugabe, the Times reported.
On Saturday, opposition leader Morgan Tsvangirai also returned to Harare, the capital, with the aim of defeating Mr Mugabe in the election on June 27. Mr Tsvangirai had planned to arrive last weekend, but pulled out after his party announced he was on an army hit list.
The Times said that for Mr Mugabe - who has been in power for 28 years but faces a fight for his political life after losing the first round to Mr Tsvangirai in March - to leave last week suggested the visit was urgent.
He is thought to have had cancer for some time, it said, adding that observers noted the trip might indicate a deterioration in his condition.
In recent years, the South-east Asia region has become a favourite destination for the president and his much younger wife, Grace, who are banned from Europe and America. The Times said most of Mr Mugabe's assets were transferred to the region after Western sanctions were imposed.
It said family members continued to be educated there and that Mr Mugabe has a close relationship with former Malaysian Prime Minister Dr Mahathir Mohamad.
The Times also reported that the man who has increasingly taken charge of security in Zimbabwe is Mr Emmerson Mnangagwa, head of the Joint Operations Command (JOC), who was widely associated with a massacre of 20,000 Ndebele tribesmen in the 1980s.
Mr Mnangagwa, whose reputed brutality earned him the nickname "The Crocodile", made his way to power by becoming indispensable to Mr Mugabe. He and his tight-knit group of top military and security officials in the JOC are directing the current violent course of events, said the Times.
They are running Mr Mugabe's campaign and masterminding the violence being unleashed against Mr Tsvangirai's supporters, the paper said. Mr Tsvangirai's arrival at Harare airport signalled his determination to contest the run-off, despite concerns that it will be rigged.
"I feel quite safe," he said as he left South Africa, where he had spent much of the past weeks lobbying regional leaders.