Biti allegedly faces charges for inciting violence over the disputed result of last week’s elections.
“He was arrested at the Zambian border,” Biti’s lawyer Nqobizitha Mlilo told AFP, adding by text message that he was trying to seek asylum.
In last week’s vote, President Emmerson Mnangagwa narrowly retained power, but the opposition MDC party has accused the electoral authority of rigging the result.
Supporters of the MDC took to the streets on 1 August to protest the alleged fraud, triggering a brutal response from the military which opened fire on the demonstrators leaving six people dead.
The day before the protests — and before the final presidential results were announced — Biti held a press conference at the Movement for Democratic Change’s (MDC) headquarters in Harare claiming victory for the party.
Biti, who also alleged electoral fraud, is a senior figure in the MDC alliance and was the respected finance minister in Zimbabwe’s troubled 2009-13 power-sharing government.
The police were not immediately available to comment.
The state-run Chronicle newspaper said on Tuesday that Biti was among nine suspects being sought for inciting the protests when the army opening fire.
Police detective Portia Chinho told the paper they were wanted for “participating in a gathering with intent to promote public violence”.