BEIJING (AFP) - The Communist chief of China's sixth-biggest city Guangzhou is being investigated for corruption, Beijing said on Friday, the latest official to fall in a high profile campaign against graft.

Wan Qinliang is being probed for "serious violations of discipline", the ruling Communist Party's Central Commission for Discipline Inspection said in a statement on its website, without giving details.

The term is usually a reference to corruption.

As Guangzhou's Communist Party secretary, Wan ranks above the mayor and is the most senior official of the city, the capital of the southern province of Guangdong, which neighbours Hong Kong.

Mr Xi Jinping took office as president last year warning that graft could destroy the party and vowing to root out corrupt officials from high-ranking "tigers" to low-level "flies".

Corruption causes widespread public anger and the drive has been widely publicised. But critics say no systemic reforms have been introduced to combat it, while citizen activists calling for such measures have been jailed on public order offences.