US investigators traced online searches for a deadly poison back to a device owned by murder suspect Yorgen Fenech. 

Sources told Times of Malta that the US Federal Bureau of Investigation last year flagged online searches for a poison known as potassium cyanide, to Fenech, just a few months before he was arrested for the murder of Daphne Caruana Galizia.  

The searches were made on what is known as the dark web, a part of the internet that is not indexed by search engines as it is considered a hotbed of criminal activity.

These sites have been linked to organised crime, including narcotics trafficking and illegal arms dealing.  

The individual making the searches used a user name and password to access the dark web site, and accessed pages for the potential purchase of enough of the poison to kill an adult male weighing 80kg. 

Sources said the matter was the subject of a police investigation, and while it is not clear who was the intended target of the poison, investigators have not excluded that it was intended for Melvin Theuma, the murder middleman, turned State witness in the case. 

This, however, is just a theory at this point, the sources added. Another theory, they said, is that the poison could have been for himself.

On Monday, homicide inspector Kurt Zahra confirmed in court that police were investigating an alleged attempt Fenech made to procure a fast-acting potentially deadly chemical that is used as a poison.

Questions about that alleged attempt, made by parte civille lawyer Jason Azzopardi, immediately drew protests from Fenech’s defence team.

Police were also looking into other issues they had discovered in the course of their investigations, the inspector added.