Ms Macheka is the daughter of strong Zanu-PF cadre Cde Joseph Macheka.
It is alleged Mr Tsvangira's younger brother constantly fed the former PM false stories about Ms Macheka's infidelity.
This was one factor that destabilised the marriage.
"He would pay his party security aides to spy and track on Elizabeth, paying them as much as US$6 000. The party spies would also cook stories. When Elizabeth discovered this, she confronted Mr Tsvangirai who did not deny it," one source said.
Yesterday, Mr Tsvangirai said he would handle these matters with his wife.
"We will sit down and discuss them as two mature adults," he said.
He also denied plans to marry Ms Leah Mhundwa.
Mr Tsvangirai said although Ms Leah Mhundwa was "given" to him by her family as part of a Shona cultural practice (chimutsa mapfihwa) following his wife's death in a car accident in 2009, he never intended to formally marry her.
Sources maintain Mr Tsvangirai often visited Ms Leah Mhundwa behind Ms Macheka's back, further destabilising his marriage when the alleged trysts became known.