A Pakistani appeals court has rejected former Prime Minister Nawaz Sharif's appeal over a seven-year prison sentence for corruption and refused to grant him release on medical grounds.

The Islamabad High Court's two-judge panel announced its ruling on Monday after the appeal hearings concluded last week. Sharif's aide Shahid Abbasi says the former premier's team will take the case to the Supreme Court.

Sharif is in custody in hospital where he is being treated for heart-related issues.

He and his family members have been embroiled in several trials on corruption charges after the Supreme Court disqualified him from office in July 2017.

An anti-graft tribunal had sentenced Sharif to 10 years in another corruption case last year but that sentence was later suspended pending appeal.