A Zimbabwean cameraman abducted from his home in the capital, Harare, last week has been murdered.
Footage of Mr Tsvangirai's injuries was shown around the world
Edward Chikomba's badly beaten body was found at the weekend in bushes next to a road some 50km west of Harare.
Correspondents say the reason for his killing is not yet clear, but there are concerns it is linked to the smuggling of news footage out of Zimbabwe.
Meanwhile, unspecified action has been threatened against businesses that shut during the trade union general strike.
Minister Obert Mpofu told Zimbabwe's Herald newspaper that firms which closed on Tuesday or Wednesday had been given 24 hours to state their reasons in writing.
The strike, which was poorly observed, was called to protest at Zimbabwe's deepening economic crisis
Tension has been high in the country since police broke up a prayer meeting last month organised by the main opposition party, detaining and beating several government opponents.
More than 80% of Zimbabweans living in poverty and inflation is running at more than 1,700% - the highest in the world.
The BBC's Peter Greste says with inflation so high and four out of five workers without a job, there is plenty to complain about, but opponents of President Robert Mugabe are both broke and scared.
Mr Chikomba was a freelance cameraman who had worked at the state-run Zimbabwe Broadcasting Corporation (ZBC).
Police were deployed across Harare during the strike
Eyewitnesses say Mr Chikomba was seized from his home by armed men last Thursday.
The newzimbabwe.com says he had links with the opposition Movement for Democratic Change (MDC).
"He was coming from a popular pub which almost exclusively caters for MDC supporters," a friend told the website.
Correspondents say the police informed his family that a body had been found, but have not commented further.
"It's not clear whether the murder was a message to the media or a political killing," a former colleague told the UK's Independent newspaper.
The paper says ZBC staff have been sacked or harassed in the past under suspicion of selling pictures to foreign broadcasters.
Television pictures showing beaten up MDC leader Morgan Tsvangirai were broadcast around the world in March.
According to UK-based SW Radio Africa, ZBC journalists say there is a probe under way to discover how footage of President Mugabe's February birthday party was leaked.
Local journalist Gift Phiri of the UK-based The Zimbabwean newspaper was detained and badly beaten by police on Sunday.