Prominent Iranian dissident journalist Akbar Ganji says he will give himself up to the authorities soon.
Ganji has been outspoken about upcoming elections since he left jail
Mr Ganji went missing earlier this week while on temporary medical leave from jail after going on hunger strike.
In a typed letter distributed by his wife, he denied he was in hiding and stressed he had done nothing wrong.
Mr Ganji has served five years in jail after linking some senior figures in Iran to killings of intellectuals and dissidents in the late 1990s.
He has been missing since Tuesday evening, when he went out with friends.
That same night, during his absence, judiciary officials arrived at his house with a warrant to return him to prison.
Tehran's hardline chief prosecutor said he had evaded arrest and was on the run.
In his letter to the media, Mr Ganji said he had been very surprised to read statements in the media that he was supposed to be on the run.
He said he was not in hiding - he had not done anything wrong.
However, he gave no details about his whereabouts, and did not specify when exactly he would give himself up to the authorities.
Mr Ganji insisted he was not afraid to return to prison; although he remarked that when he did return, he expected he would be put into solitary confinement.
He accused the Iranian authorities of not keeping their word.
Judiciary officials, he said, had tried to return him to jail despite the fact that the judiciary had earlier said his temporary medical leave had been extended.
He suggested the reason they had tried to re-imprison him was because he had spoken to the press after his release.
Since leaving prison, Mr Ganji has been extremely outspoken in his criticism of Iran's clerical system of government.
He said that voting in next week's presidential elections would help Iran's supreme leader Ayatollah Ali Khamenei legitimise what he described as his personal dictatorship.
Such a direct attack on the supreme leader - regarded as God's representative on earth by his supporters - is extremely rare in Iran.