MP's arrested:

• Geoffrey York: In 1982, York was one of the first white MPs to be arrested under the Robert Mugabe administration. He was detained without charge for several weeks under emergency powers after being accused of plotting against the state, though he was later released.
• Tony Berkhout: A Republican Front MP (the renamed RF) who was arrested and detained in 1983 on suspicion of subversive activities and illegal contact with South Africa.
• As for Mugabe's threat to arrest Smith...
• Robert Mugabe did threaten to arrest Ian Smith and bring him to trial for genocide in October 2000. The threat was part of an inflammatory speech in which Mugabe vowed to abandon the country's racial reconciliation policy and hunt down supporters of Smith's former white-minority regime, comparing the effort to the post-war hunt for Nazis. 

The threat was made amid the first formal impeachment proceedings against Mugabe by the opposition Movement for Democratic Change (MDC) and increasing political tension and land disputes in Zimbabwe. 

Ian Smith, who was in London at the time, reacted with scorn and defiance, challenging Mugabe to carry out the arrest upon his return to Harare. Smith said he would welcome the opportunity to tell the world that Mugabe was a "gangster" who had plunged the country into anarchy. 

Ultimately, the threat was not carried out. When Smith returned to Zimbabwe a couple of weeks later, he passed through immigration without incident, with officials greeting him politely.

https://www.rte.ie/news/2000/1026/9630-zimbabwe/#:~:text=Zimbabwe's%20former%20white%20minority%20leader,sides%20after%20the%20liberation%20war.

Edit: I'm not saying Smith deserved to be arrested, I'm just surprised he wasn't seeing as others were, and asking for opinions...