Nigeria's ruling party on Monday won back control of the key oil-producing state of Rivers, official results showed on Monday, after rigging claims by the main opposition.

Nyesom Wike, from President Goodluck Jonathan's Peoples Democratic Party, won 1,029,102 votes, while Dakuku Peterside, of the All Progressives Congress (APC), won 124,896, the electoral commission said.

The APC, which previously controlled the state, described the result as "a rape of democracy".