Colombo: One of the suspects in Colombo blasts, that killed over 250 people and injured nearly 100 others, was monitored by Indian Intelligence agencies three years ago for links with Islamic State suspects, investigators told Reuters.

According to the report, Sri Lanka based software engineer Aadhil Ameez was the link between the groups responsible for carrying out coordinated blasts in Sri Lanka on Easter Sunday, Sri Lankan agencies believe.

The report also said that 24-year-old engineer was taken into police custody on April 25, an official confirmed the news to the agency. However, his arrest was not made public. The officer refused to divulge more details.

The investigators on the Indian side has been surveilling Aadhil since 2016. Further, they have also named him in the two chargesheets filed in the courts against suspected Islamic State operatives as being one of their contacts, said the Reuters report.

India is also providing assistance to Sri Lankan authorities in the matter.

Having no lawyer and under Sri Lanka’s newly imposed laws post-attack, Aadhil could be held indefinitely.

The suspect’s father has dismissed the report of his son being involved with the plotters of the Sri Lanka blasts, saying “allegations are lies”.

As per the investigators, Aadhil was one of the main plotters and helped in the training process.

“He was the main technology person for them,” Reuters quoted one of the officials involved in the investigation.

Sri Lanka has been on the edge since the April 21 horror when suicide bombers exploded themselves in three churches and three luxury hotels besides two other places. Most targets were in Colombo. The killings were the worst to hit Sri Lanka since the end of the civil war a decade earlier. The unrest was triggered on Sunday after a group of people stormed into Chilaw town following the Facebook post by a Muslim shopkeeper about “an attack plan”.

Sri Lankan authorities say most of the 150 people suspected to have been linked to the last month’s attacks have died or been arrested but many still fear that the government has not caught all potential militants.