A Kuwaiti judicial tribunal investigating graft allegations has cleared the former prime minister of any wrongdoing in a series of financial transactions made abroad, the law firm representing him said on Thursday.

Sheikh Nasser Al-Mohammad Al-Sabah's government resigned last year after some opposition lawmakers accused it of having made a series of illegal financial transfers via Kuwait's overseas embassies.

Sheikh Nasser, a nephew of Kuwait's ruler, had repeatedly denied any wrongdoing. It was the first time that a complaint against a former prime minister and a member of the ruling Al-Sabah family had been investigated at such a high level in the Gulf oil producer.

Sheikh Nasser was "cleared and exonerated on all criminal charges filed against him", a statement from the law firm representing him said.

The tribunal found that the funds were intended for "humanitarian issues and to satisfy Kuwait's international obligations", the Salman Duaij Al-Sabah law firm said. The transfers were "of a diplomatic and political nature in the best interest of the state of Kuwait", it said.

Sheikh Nasser had been questioned by a tribunal that has jurisdiction over past and present ministers as part of an ongoing inquiry into alleged graft under the previous administration. Members of the closed-door tribunal do not comment to the media.

Sheikh Nasser remains under investigation by a less-powerful parliamentary panel. When the allegations first came to light last year protesters and opposition lawmakers staged a series of protests outside parliament that culminated in the storming of the chamber, forcing the government to resign and triggering the dissolution of the assembly.

A snap election in February gave Islamist-led opposition candidates a majority in parliament. Since then, those opposition MPs have quizzed the current prime minister, Sheikh Jaber Al-Mubarak Al-Sabah, over his handling of the investigation, highlighting continued discord in the region's most outspoken parliament. - Reuters