ABUJA (AFP) – Election campaign chief for Nigeria's former military ruler, questioned over the independence day bombings, has sued the country's secret police for harassment, documents showed on Tuesday.

Raymond Dokpesi, a campaign director for Ibrahim Babangida has taken the intelligence services to court for "unwarranted infringement" of his freedom.

Babangida is running against President Goodluck Jonathan at the ruling Peoples' Democratic Party primaries for next year's presidential vote.

Dokpesi, who also owns one of Nigeria's leading private television stations, said he was detained and questioned for nine hours two days after twin car bombs went off during independence day celebrations.

He said he has been reporting to the State Security Services (SSS) for further questioning.

The media mogul who has denied any involvement in the blasts, wants the court to rule that his "arrest, detention, harassment and undue questioning" violate his rights.

He is seeking 100 million naira (about 670,000 dollars) in damages, according to the documents filed on Monday and seen by AFP. A hearing date is yet to be set.

SSS arrested nine suspects after the October 1 blasts. It said all of them have links to Henry Okah, a former rebel from the oil rich Niger Delta.

Okah, who lives in South Africa, has been charged under that country's anti-terrorism laws and is due back in court on October 14.

The explosions went off a few hundred metres (yards) from venue of official parade in the capital, killing 12 people.