Mugabe’s meeting with the leader of a new opposition party last weekend appears to have ruffled the feathers of new President Emmerson Mnangagwa.
Some analysts say this latest move is an attempt to destabilise the ruling Zanu-PF ahead of elections later this year.
And it was reportedly followed by a raid on the home of the former president, who was forced to quit when the military briefly took power in November and Zanu-PF lawmakers launched impeachment proceedings.
Military detain Mugabe guards
At least four security officers at Robert Mugabe’s house were detained by members of the military on Wednesday when Mugabe had already left for a private visit to South Africa, according to a local newspaper.
"The Zimbabwean Independent paper said the security guards, including Mugabe's chief security officer, were taken to a Harare army barracks and then interrogated about what visitors Mugabe has been receiving, whether or not he talks about politics," correspondent Ryan Truscott told RFI.
One private newspaper reported that the guards were questioned all day and denied food or water but released later.
Mugabe's wife Grace was at home at the time and she is said to have been shaken by the event.
New party set up
The detention appears to have stemmed from a visit to Mugabe last weekend from Ambrose Mutinhiri, a former army officer and cabinet minister under Mugabe, Truscott says.
Mutinhiri resigned from the ruling party last week, saying he objected to last year's military takeover.
Mutinhiri has just become the president of a new political party called the National Patriotic Front (NPF).
"We know little about it," says Truscott. "But it's rumoured to have the support of the Mugabes and G40, which was the faction of the ruling party that supported Grace Mugabe.
"Members of the government appear to be worried that Mugabe and his wife are maybe planning some sort of political comeback. Some officials this week accused Mugabe of trying to destabilise the ruling party."
Mnangagwa's patience tested
Until now Mnangagwa has been careful to show only respect towards his predecessor, Truscott says. He has said that Mugabe made no mistakes while in office and that he considers him a father.
But it looks as if his patience is now being tested.
"Since he stepped down, Mugabe has had no platform so to speak and the information we've had has been leaked, most recently from his private birthday party," Truscott reports. "It does seem that Mugabe isn't happy about the military takeover in November and he's determined now to try and speak out against the way he was removed from office.
"Mnangagwa told a meeting of the ruling party's youth wing this week that he himself isn't actually happy about what he's been reading in the press with regards to Mugabe and his links to the new party but he did say he wouldn't take up a definite position until he was clear about the facts.
"Some analysts say if the new party is really linked to Mugabe, then it could prove to be a spoiler because Mugabe probably still enjoys a lot of support in some of the rural areas and if the former president gives his backing to a party other than the ruling party then it could split the vote and weaken Mnangagwa’s chances."
Others, continues Truscott, say Mugabe is a has-been and that this new political party has got no chance of gaining traction with voters.
"Many voters have got used to the idea of Mugabe being permanently in retirement and so they won't be able to stomach the idea of him or his wife coming back on the scene."