A Pakistan high court on Monday suspended jailed former prime minister Imran Khan's 14-year graft sentence, his party said, the longest prison term the popular opposition leader was serving.

Khan, 71, remains jailed on two other cases including treason and illegal marriage with sentences stretching up to a decade.

A spokesman for his Pakistan Tehreek-e-Insaf (PTI) party said the Islamabad High Court dropped the former cricket star's sentence from an anti-corruption court over selling state gifts, with an appeal against the conviction pending.

The trial court gave "limited counsel access but also had reached the decision in haste without allowing defence to conclude arguments," spokesman Ahmed Janjua said.

Khan was hit by a trio of sentences in the days before Pakistan's February general elections. Analysts said it was a bid to sideline the former prime minister and his PTI party from the poll.