The Zimbabwean prime minister has not commented publicly on the apparent land grab by his relative, but sources close to the Movement for Democratic Change (MDC) party leader said he was "not happy" about the events – and that they risked overshadowing progress in the unity government.
Mr. Tsvangirai, who shares power in Zimbabwe with President Robert Mugabe, is currently on a US and European diplomatic tour to raise money for his beleaguered country. Britain pledged an extra £5 million ($8.2 million) Monday, after Prime Minister Gordon Brown held a landmark meeting with Tsvangirai. Mr. Brown pledged more help if reforms gained momentum, expressing concern over whether the unity government was making progress.
Tsvangirai's diplomatic entourage includes politicians from Mr. Mugabe's ZANU-PF party, whose travel bans were lifted by the European Union ahead of the first official EU-Zimbabwe meeting in seven years last week. Mugabe, who has ruled Zimbabwe since 1980, agreed last February to share power with Tsvangarai in the wake of a disputed 2008 national election.
But his niece's land claim has highlighted deep divisions between the MDC and ZANU-PF factions over one of the country's most controversial policies.
Tsvangirai opposes farm invasions, calling for the rule of law to be respected. But he has angered farmers' leaders by describing some attacks as "isolated incidents." They claim he has been powerless to prevent nearly 80 farm occupations since the unity government came into being in February.
While he plays down the farm violence, Mugabe and ZANU-PF have insisted there was "no going back."
Who has gotten the land?
Mugabe began his policy of farm redistribution in 2000, claiming he wanted landless peasants to benefit from farms owned by whites. But critics say most have gone to political allies. Of the 4,000 farmers in Zimbabwe in 2000, only an estimated 400 are left, leaving the country desperately short of food and leaving tens of thousands of workers unemployed as land lies idle.
Since last December, around 150 white farmers have faced court action for "illegal occupation" of their property while the government has ignored rulings from Southern African Development Community tribunals that say its policy was illegal.
According to farm owner John Cremer and Zimbabwean media accounts, Ms. Chihombori, who has US citizenship and lives in the US, began the land seizure in November with the help of her sister, who lives in Zimbabwe. Since then, she has become embroiled in legal arguments about ownership of the farm.
The seizure might have gone unnoticed had Chihombori not accompanied her uncle to the inauguration of South African President Jacob Zuma last month.
After her link to Tsvangirai was established, Chihombori withdrew her land claim. However, she has told the local Zimbabwe media it was only "for the time being."
Zimbabwean media have suggested her uncle put an end to the land claim.
"Tsvangirai is not happy about the latest developments, especially surrounding the issue of Dr. Chihombori," says a deputy minister in the inclusive government who is a close confidante of the prime minister. "It was not his intention to hog the limelight for the wrong reasons, because of a relative. He thinks she is free to do what she wants, but without his name involved."
MDC spokesman Nelson Chamisa said his party did not condone land invasions. "We are of the view that the current status quo must remain as we take stock of the land reform in the unity government," he says. "As a party, we want action to be taken against the new invaders so that our transitional government can be credible."
A farmer's view
Mr. Cremer, the farm owner who has previously described the land seizure as "greed," said things had calmed in recent days. "They [the invaders] have left the farm and everything is back to normal," he says. "But I'm not at liberty to further comment on this issue because it has become political."
Cremer was born on the farm, which was originally more than 700 hectares before 650 were given away in 2002 under the government's land redistribution laws. The Cremers now have about 60 hectares, including buildings, on which they grow flowers and vegetables for export and local markets. Much of the distributed land is lying idle.
Commenting on the Cremer seizure, a senior ZANU-PF spokesman said: "Those who are occupying the farms were given offer letters long back. They are simply taking their positions. It is the hostile media which is portraying this as a new phenomenon.
"Our position as a party is that the land reform is irreversible and we support those who are taking up their farms if they have offer letters from the relevant authorities. The land reform is not just benefiting black farmers but white farmers, too."
However, the Commercial Farmers Union says it is losing faith in the unity government.
"The same government that destroys the production goes begging for support we don't really need," says Deon Theron, the union's vice president. "Put us back on the farms, and we will start producing again."
• A reporter in Harare could not be named for security reasons.