Toendepi Shonhe was arrested and charged last Saturday after he allegedly assaulted the husband of an MDC information officer he was bedding in a Bulawayo hotel.
MDC spokesman Nelson Chamisa told a news conference in Harare that the party had ordered a "thorough investigation into allegations of misconduct, professional deviance and unacceptable behaviour … involving Toendepi Shonhe, and an employee in the information and publicity department."
Media reports said the woman involved in the scandal is 27-year-old mum-of-one, Sandra Mutsimba. She is also suspended pending investigations.
Chamisa said: "The investigation is meant to either locate or negate abuse of office, the presence or otherwise of acts of misconduct and the violation of MDC code of ethics and values that should guide all MDC officials, elected, appointed and deployed.
"While acknowledging the desirability of the privacy of the aforementioned two, the party unreservedly condemns any commission or omission that undermines the values and morals of the ‘Party of Excellence’."
Chamisa, also the Minister of Information Communication Technology, said Shonhe would receive a "fair hearing" before a three-member committee which will lead the probe comprising national executive members Norman Mabhena, Lucia Matibenga and Harare lawyer Innocent Chagonda.
The committee must "carry out the investigations and complete them within the next eight days", Chamisa added.
Shonhe was detained overnight on Saturday after an altercation with Sandra’s husband at Zaks Place hotel at the corner of 14th Avenue and Robert Mugabe Road.
Police said the woman’s husband, who was also booked there, noticed her vehicle in the car park and enquiries with hotel staff took him to a room booked for the night by the two lovebirds.
Police were called after the two men clashed. A video of the incident has been handed over to a local newspaper.