( CNN ) -- Iran should release seven Baha ' i prisoners accused of espionage because it does not have any evidence against them , their lawyer Shirin Ebadi told CNN on Saturday . Attorneys Abdolfattah Soltani , left , and Shirin Ebadi , shown in Tehran in 2004 . `` In the files , in the case basically , there is nothing , no reason that basically convicts them , '' said Ebadi , a Nobel Peace Prize laureate . The trial will begin Tuesday despite the fact that one of their lawyers is behind bars and Ebadi is outside the country . Other attorneys can be appointed , Hassan Haddad of the Prosecutor 's Office in Tehran told the state-run Islamic Republic News Agency . But the court must recognize the replacements , who are colleagues of Ebadi at her Tehran-based Defenders of Human Rights Center , not appoint other lawyers , Ebadi said . The imprisoned lawyer , Abdolfattah Soltani , is a well-known advocate with the human rights center . He was arrested in the aftermath of Iran 's disputed June 12 presidential election and is being held at Evin prison , the same place where his clients are detained , according to the International Campaign for Human Rights . He is being held on charges of taking `` measures against national security , '' Ebadi said . `` Mr. Soltani is completely innocent . '' Soltani had an opportunity to leave prison , but under conditions he chose not to accept , Ebadi said . Along with not giving any interviews after his release , Soltani would also have to end his work with the human rights center and no longer support Ebadi , she said . In another attack on the law firm , a lawyer was arrested after agents entered the center with guns , searched each room and then declared that they found opium on the premises , Ebadi said . That lawyer , whose family had been harassed by police , accused the agents of planting the opium , she said . Ebadi was on a speaking tour when Soltani was arrested and has not returned to Iran . The firm founded by Ebadi took up the case of the seven Baha'is last year . They are accused of spying for Israel , spreading propaganda against the Islamic republic and committing religious offenses . The Baha ' i International Community , which has a delegation to the United Nations , denies the allegations . The evidence against the defendants includes communication from Israel , but that is because the Baha ' i World Center has its headquarters in Israel , said Kit Bigelow , director of external affairs at the American Baha ' i Community . Prosecutors are calling that communication espionage , she said . Human rights groups have demanded the release of the prisoners and accused the government of targeting them because of their religious beliefs . The Baha ' i faith originated in 19th-century Persia , and while modern-day Iran does not recognize it , the government denies any mistreatment of the members of the largest non-Muslim religious minority . The International Campaign for Human Rights in Iran has reported a rise in persecution of Baha'is in recent years , including cemetery desecration , arbitrary detention , home raids , property confiscation , work expulsion and denial of basic civil rights . The case of the seven Baha'is has drawn global attention . Roxana Saberi , the Iranian-American journalist freed from Evin prison earlier this year , spoke on their behalf , as have Human Rights Watch and the U.S. Commission on International Religious Freedom , an independent bipartisan federal commission . The defendants face the death penalty if convicted . Six of the defendants were arrested in May 2008 at their Tehran homes , and one was arrested in the eastern city of Mashad in March 2008 , said Diane Ala ' i , the Baha ' i International Community 's representative to the United Nations . The defendants were held under solitary confinement for the first five months of their incarceration , she said . The investigation into the charges against the prisoners concluded months ago and the trial was initially scheduled to start in July . Iran has continued to hold them in Evin prison without access to their lawyers and with minimal contact with their families , Ala ' i said . CNN 's Moni Basu contributed to this report .
Seven Baha ' i prisoners accused of espionage to go on a Tuesday in Iran . Baha'is are accused of spying for Israel , and propaganda against Iran . One of prisoners ' attorneys is in jail ; another is outside the country . Case of the seven Baha'is has drawn global attention .