He was arrested at his Ngara clinic by police investigating the case.
His Fig-Tree Medical Centre was shut down as detectives appeared to zero in on Mwiti who failed to get an anticipatory bail in court.
Police and officers from the Kenya Medical Practitioners and Dentists Board also searched Muchiri's clinic and left with undisclosed documents.
The board CEO Daniel Yumbya said Muchiri was arrested because his clinic is not licensed.
Yumbya said Muchiri offers consultancy services, yet he is not a consultant. Muchiri also has not renewed licence, he said.
Meanwhile, the High Court yesterday declined to issue Mwiti with an anticipatory bail.
Mwiti is accused of raping a journalist after subjecting her to a forcible HIV test, allegedly conducted by Muchiri, on March 21.(Read story here)
