"I've committed no crime."

Those are the words of Zimbabwe's protest pastor Evan Mawarire who has been filmed in handcuffs at Harare's main police station shortly after his arrest on his return from six months in exile.

In the second of three short videos posted on Wednesday evening on the Facebook page of his ThisFlag movement, the 39-year-old father-of-three says: "Unfortunately I've been arrested."

"We will get through this. This is home for me. I've committed no crime and I'm allowed to come back home."

Lawyer Harrison Nkomo has told the private Zimbabwe Independent newspaper that Mawarire is being charged with trying to overthrow a constitutionally elected government.

In the first video, Mawarire is seen twisting his handcuffed wrists as he thanks lawyer Fadzayi Mahere and others for coming to the station.

"OK guys, thanks for coming," Mawarire, who's wearing a checked shirt, says. Mahere confirms she was "so excited" to hear of his return.

But there's no mistaking the tiredness and sense of let-down in the short clips. Many Zimbabweans were not aware that the pastor, who became the face of the country's hopes for change last year, was heading home.

The pastor launched his protest movement last April, posting short videos online that captured a generation's sense of frustration both with the government of President Robert Mugabe and the ineffectiveness of Zimbabwe's opposition parties.

Mawarire organised a successful nationwide stay-away in July but was arrested soon afterwards and fled into exile in the US. It later emerged that his wife Samantha was pregnant. She had a baby in November. State radio has not confirmed his arrest.