Amid mounting reports of a series of executions carried out by the Iranian authorities in recent days following the disputed presidential elections last month, an Iranian lawyer has given this reporter an insight into the legal struggles he is facing in trying to defend some of those now in detention for participating in opposition protests. The state-run Fars news agency reported that 20 people were hanged at the Karaj prison west of the capital on Saturday, and another 14 executions elsewhere in Iran have been reported by state media since Wednesday, including six hangings at Teheran's Evin Prison. Many of those executed have been described in state media as drug traffickers - a charge often leveled at dissidents. Iranian police say that about 1,000 people have been detained for involvement in the public protests that erupted after June 12 presidential elections. Mir Hossein Mousavi, the defeated candidate who has branded the victory of incumbent President Mahmoud Ahmadinejad fraudulent, has been laying low since last Wednesday while still challenging the results. On Saturday, a top aide to Iran's supreme leader said Mousavi was a US agent who should be tried for treason. "It has to be asked whether the actions of [Mousavi and his supporters] are in response to instructions of American authorities," wrote Hossein Shariatmadari, in an editorial in the conservative daily Kayhan. Shariatmadari is a close adviser to Supreme Leader Ayatollah Ali Khamenei. He added that Mousavi was trying to "escape punishment for murdering innocent people, holding riots, cooperating with foreigners and acting as America's fifth column inside the country." He called for Mousavi and former reformist president Mohammad Khatami to be tried in court for "horrible crimes and treason," adding that there were "undeniable documents" proving Mousavi's foreign links. In a telephone interview with this reporter, an Iranian lawyer spoke of trying to defend some of those arrested, focusing on cases "where the circumstances and accusations surrounding the detainees can be proven inadequate." He said one of his clients had been accused of crimes against the state and disturbing the nation's security - charges that could carry a sentence of 10 to 15 years of imprisonment. The young man was arrested a week after the elections "because he was out on the streets with other dissenters. The security forces took his cell phoneâ€¦ but [fortunately] the young man did not have any [problematic] pictures or recordings, which could help his case." He said a confession and a payment equivalent to $20,000 to the establishment, "as reparation," would resolve the case. In such a confession, his client would also take "responsibility for his misguided actions and agree not participate in further protests." However, he went on, his client "is not willing to sign the confession. He keeps on saying that it is against the basic principles of Islam to lie, so he won't sign what he calls a lieâ€¦ This makes my job more difficult." The lawyer said he was trying to argue on his client's behalf that he had been "led astray" and had been manipulated by "other major players of the opposition." Asked if he believed this was truly the case, he said: "I believe in getting my clients released, and I am willing to do what it takes." When asked if his client had been beaten or suffered from abuse while in custody, the source said: "I would like to refrain from answering that question. I don't want to jeopardize not only my client's hearing, but future ones as well. What I can say and am authorized to say is this: Any injures received by my client were subject to sudden movements by the crowds out on the streets; therefore they were accidental." Many detainees are being held at the notorious Evin Prison - where six of the hangings took place last week. Evin, with a capacity in the thousands, was built by the Shah's regime as a modern security prison to house political dissidents, but it became the Islamic Republic's most dreaded such facility and the reported site of large numbers of political executions. Earlier last week, families of some of those detained gathered in front of the jail but were dispersed by security forces. "They won't even let lawyers inside the compound," said one source. "There are many families with loved ones inside or who think that they have loved ones inside. There are many rumors going around. Some are afraid that the prisoners are being tortured to death or hanged under false identitiesâ€¦" This source spoke of wealthier families paying a fee for the release of detainees, in transactions conducted outside the prison. It was those who can't afford such transactions who gathered last week, the source said. The six people hanged at Evin last week were not named and were described as murderers by one judicial official. The Teheran source said he believed, however, that they were opposition protesters. "This regime has proven itself capable of committing horrific acts and covering them up," the source said. "Look what they did out on the streets. It is foolish to think that they will show mercy to those behind prison walls." Ominously, senior cleric Ayatollah Ahmad Khatami said on Friday, "Anyone who takes up arms to fight with the people is worthy of execution." Those who disturbed the peace and destroyed public property were "at war with God" and should be "mercilessly dealt with," Khatami said in a nationally televised sermon. The regime has appointed its most widely feared and callous prosecutor, Saaed Mortazavi, to interrogate reformists and other high profile activists captured during demonstrations. Several families of detained protesters have confirmed that the interrogation of prisoners is now being headed by Mortazavi. As prosecutor-general of Teheran since 2003, Mortazavi acquired infamy for his role in the death of a Canadian-Iranian photographer, Zahra Kazemi, who was tortured, beaten and raped during her incarceration in 2003. One year later, Mortazavi was responsible for the arrest of more than 20 bloggers and journalists, who were held for long periods of solitary confinement in undisclosed locations. He also played a crucial role in the arrest and trial of the American-Iranian journalist, Roxana Saberi, who was arrested in February, sentenced to eight years in prison for spying, and released in May. Since the unrest, Mortazavi has rounded up many prominent reformists, including Saeed Hajarian, a close aide and friend of former president Mohammad Khatami. Hajarian, who is being held at Evin, is a prominent reformist theorist who survived an attempted assassination in March 2000, at the peak of the conflicts between conservatives and reformists in Iran, and has subsequently become severely disabled. Amid unconfirmed rumors that he has died in Evin, Human Rights Watch has asked Iranian officials to release Hajarian or transfer him to a medical center. Iran's ruling clerics have called the presidential elections "pure" and "healthy." Notably, however, only one of top clerics in the religious center of Qom has congratulated Ahmadinejad on his re-election, indicating their displeasure with the disputed results. Some have even openly supported Mousavi, condemned the government's tactics against demonstrators and expressed their own doubts about the election results. "A large portion of the people have not been convinced over the ambiguities in the election... Due to lack of public support, the government may face legal and civil problems and a lack of competency," Grand Ayatollah Youssef Saanei said in a statement on his Web site late Friday. Saanei is one of the top nine most influential clerics in the country and has substantial following among Iranians, though he is on poor terms with the government. "I remind all forces required to protect the ... people that no order should be an excuse or permission to violate the rights of the people ... let alone killing or injuring them," his statement added. Jerusalem Post staff and AP contributed to this story.