DUBAI (Reuters) - The spiritual leader of Bahrain's Shi'ite Muslim majority went on trial on Wednesday on charges of collecting donations illegally and money laundering in a case that has increased tensions in the Western-allied Gulf Arab state.

Ayatollah Isa Qassim, who also faces expulsion from the country after authorities revoked his citizenship last month for alleged foreign links and fomenting violence, says the charges are part of a political crackdown on majority Shi'ites to stop them from pushing for political reforms.

A prosecution statement said Qassim and two others accused in the same case did not appear in court despite having been informed of the trial. The hearing was postponed until Aug. 14.

The case revolves around a Muslim tax known as Khums which in Shi'ite Islam is collected by the most senior cleric whom individuals follow.

The case arose after investigators discovered more than $10 million in an account held by Qassim, a sum which the prosecution said was intended "to escape legal monitoring", according to the statement.

The prosecution also said other holdings were in real estate.

Qassim and other senior clerics have said the funds are part of Shi'ite Islamic tradition, which allows senior clerics to collect the tax and spend it in the interest of ordinary Muslims.

Tensions have risen in Bahrain following a series of government security moves including the dissolution of the main opposition al-Wefaq group.

United Nations Secretary General Ban Ki-moon earlier this month called the dissolution of al-Wefaq “the latest in a series of restrictions” on human rights in Bahrain.

(Reporting by Sami Aboudi; Editing by Mark Potter)