All Ceylon Makkal Congress (ACMC) Leader Minister Rishad Mathiudeen's brother was taken into custody by the Army over the Easter Sunday explosions.
The arrest was made by the Army intelligence unit, the Army Media Unit confirmed a short while ago.
The Minister's brother, who was arrested in Vavuniya, has been handed over to the Police for investigations.
Bathiudeen's brother is believed to be a businessman by profession.
Addressing a press conference yesterday, SLFP MP S.B. Dissanayake alleged that Bathiudeen's brother had maintained close business links with Mohammed Ibrahim, a spices exporter who has been arrested over the Easter Sunday explosions.
Ibrahim's two sons carried out suicide bomb attacks on two five-star hospitals in Colombo.