BANGKOK (Reuter) - Thai police said on Tuesday they had detained an opposition member of parliament on suspicion of masterminding a car-bomb explosion which killed a fellow parliamentarian's mother. Sithiporn Kam-arj, Bangkok MP for the main opposition Democrat Party, surrendered to police in the capital Bangkok and was flown to eastern Chantaburi province, where he was being held, police told reporters. Sithiporn has denied the charge but police said they were detaining him for further investigations pending a formal murder charge in court. Police investigations centred on planting of a car bomb which killed a fellow Democrat MP's mother, Pattama Fuengprayoon, in Chantaburi earlier this month. Police believe the bomb was meant to kill the fellow MP's father, Sanit Fuengpryoon, a potential candidate for the next election in Chantaburi. But Sanit's wife Pattama used the car and the bomb, triggered by remote control went off.