The deceased were crushed on the dinghy that was smuggling 112 people after passengers began to panic, according to BBC News.
Two of the men aged 22 and 19 were Sudanese nationals and one aged 22 was a South Sudanese national. They were arrested Tuesday night in a raid conducted by NCA and Immigration Enforcement officers and have completed initial police interrogations at a police station in Kent with more to follow.
The NCA Director of Investigations Craig Turner promised to find the organizers of the smuggling ring and bring them to justice.
"This tragic incident once again demonstrates the threat to life posed by these crossings and brings into focus why it is so important to target the criminal gangs involved in organizing them," he said.
"We will do all we can with partners in the UK and France to secure evidence, identify those responsible for this event, and bring them to justice."
Around 49 other migrants were rescued, but roughly 58 decided to stay on board and try to finish the trip to the UK.
The incident happened mere hours after the UK Parliament passed a bill to send immigrants to Rwanda in hopes of deterring them from making the dangerous trek by sea.