The man identified as Mohamed Ibrahim Ifthikar has been arrested at Dematagoda area in a suburb outside Colombo, Ada Derana news portal reported.
A police spokesperson said, as quoted by the media outlet, that policemen had found blue sapphires, as well as Sri Lankan and foreign money worth over Rs 10 million ($56,984) in his house in Dematagoda.
Another brother of the suicide attacker has allegedly attacked a restaurant at the luxury Cinnamon Grand hotel.
READ MORE: Two Main Suspects in Sri Lanka Terror Attacks Detained — Reports
Earlier in the day, local media reported that Sri Lankan police had arrested two main suspects in the deadly bombings, which rocked the country last Sunday.
A string of deadly bombings hit Sri Lanka on Easter Sunday leaving hundreds of people killed and injured nationwide. Over 100 suspects have been detained since the country launched a massive anti-terrorist operation and investigation into the attacks.
Daesh* has reportedly claimed responsibility for the attacks.
* Daesh (ISIL/ISIS/IS/Islamic State) is a terrorist organisation banned in Russia
