On May 1, Abtahi posted a selfie with former President Mohammad Khatami on Instagram.
The reformist Khatami, who remains popular among young people, doesn't seem to have been aware that Abtahi was taking a selfie.
Abtahi, one of the first Iranian officials to launch a blog, is very active on Instagram and other social media sites including Facebook, where he has a large following.
On his blog Webneveshteha.com, Abtahi used to posts inside stories and inside photos of government officials that he would take with his cellphone.
Abtahi was among the hundreds of reformist figures and intellectuals who were put on trial and jailed in the 2009 postelection crackdown.
At one point, he even updated his blog from prison.
The move was seen as an attempt by security officials to give the impression that prisoners were being well treated amid reports of physical and mental torture of detainees.
-- Golnaz Esfandiari