The MDC-T is pushing for an independent probe into the death of 12-year-old Christpowers Maisiri in an inferno in Headlands recently.
The party warned that Zimbabwe was headed for another bloody election unless political violence was effectively dealt with before the watershed polls.
MDC-T spokesperson, Douglas Mwonzora said it was surprising that the police and Zanu PF were already ruling out foul play, yet available evidence linked known Zanu PF supporters and officials to the suspected arson.
"The police are now being involved in a major embarrassing cover-up," he said.
"If Zanu PF and the police have nothing to hide, then let's have an independent probe by international investigators from other countries."
Mwonzora said the attack on the Maisiri family bore the signature of Zanu PF.
He said the only explanation about what happened was that there was foul play pursuant to the threats to the Maisiri family.
He said since 2000, the family had been attacked eight times by suspected Zanu PF supporters.
Mwonzora said, the commitment of President Robert Mugabe and Zanu PF to peace must be demonstrated by ordering an independent probe which the MDC-T was pushing for.
"Mugabe is talking romantically about his commitment to peace but not ordering police to arrest perpetrators of violence," he said.
"On our part as MDC, we are compiling a list of all those involved in violence, including cabinet ministers who are fanning violence with a view that they will be brought to justice."
Mwonzora said it was surprising that suspects in the murder of Christpowers had not been apprehended in the same manner the police acted when they arrested the 29 Glen View activists facing charges of murdering a police officer.
He said unless the international community, particularly Sadc intervened early, Zimbabwe's next elections would again be bloody just like the 2008 polls.
"If Zanu PF does not take these things seriously, then Zimbabwe is headed for disaster, where political party leaders indicate left but turn right," said the MDC-T spokesperson.
"This is why we are calling for Sadc intervention to deal with political violence. Zanu PF is desperate and has no answer to Morgan Tsvangirai's popularity and credibility, hence they have resorted to violence and confiscating harmless radios from people."
But Police spokesperson, Assistant Commissioner Charity Charamba insisted that there were no suspects yet in the death of Christpowers. She said preliminary investigations had shown that there was no foul play.
The police spokesperson said forensic experts were now busy analysing the evidence they collected from the scene. "Police work with evidence," said Charamba.
"Fire incidents are common. People must be patient. If anyone committed a crime, they will be arrested but so far there is no suggestion of foul play."
Zanu PF spokesperson, Rugare Gumbo said his party no longer took MDC-T complaints seriously.
"This is propaganda meant to attract their sponsors," he said.
"There is no political violence in the country and police cannot arrest people without evidence. They pointed out that Didymus Mutasa (Zanu Pf secretary for administration) was to blame, yet he was in Harare."
Gumbo said his party suspected that MDC-T staged the attack on the Maisiri family.
"The MDC-T has done all sorts of crooked things in the past," he said.
MDC secretary general, Priscilla Misihairabwi-Mushonga blamed both the MDC-T and Zanu PF for the current political violence saying the two parties agreed to go for elections before the implementation of the agreed election roadmap.
She said the MDC-T fell into the trap of Zanu PF and agreed to go for elections in July without implementing the roadmap which guarantees a free and fair election.
Mushonga said unless the issues of the rule of law, a partisan police and security forces were addressed, violence would continue and elections would not be free and fair.
"We warned the MDC-T that they were falling into a trap, but because of arrogance, they did not listen," she said.
"Some think that as long as Mugabe is in power they will win, forgetting that we are dealing with people who know nothing but beating others."