Pakistan's Supreme Court has upheld the death sentence for a former police officer convicted of killing a provincial governor he had accused of blasphemy.

Mumtaz Qadri shot and killed Governor Salman Taseer in 2011 in Islamabad days after Taseer defended a Christian woman accused of desecrating a Quran.

State-run television says Wednesday's ruling by the country's highest court came months after Qadri filed an appeal against his conviction by a trial court, which had sentenced him to death in October 2011.

Qadri still has the right to submit a clemency petition to Pakistan's president.

Under Pakistan's harsh blasphemy laws, anyone accused of insulting Islam or the Prophet Muhammad can be sentenced to death.