Opposition leader and former Iranian President Mohammad Khatami called for a parliamentary investigation into the June 12 presidential election and subsequent post-election violence.
Demonstrations turned violent in the wake the June 12 election that saw Iranian President Mahmoud Ahmadinejad claim a disputed victory. State-funded broadcaster Press TV claims as many as 20 demonstrators were killed and several others jailed in the post-election turmoil.
Khatami described the post-election climate as "contrary to religion, customs and laws regarding those in detention and their families."
The former two-term president said it was "necessary" to hold those responsible for the turmoil to the rule of law, adding the detention of opposition supporters was unjustified.
"If an offense has been committed, then first there must be precise and clear evidence, not claims that are bandied about and rumors of extracted confessions," he said.
He further called on lawmakers to form a "truly independent committee" to investigate the election process to "greatly clarify" the results.
Defeated candidate and former Prime Minister Mir Hossein Mousavi and his opposition supporters claim the outcome of the election was rigged.