The report on this is still out, but Haftar apparently paid the Islamic State in the Sahel about 2.5 million dollars to release two hostages, one Swiss and one Austrian, who were kidnapped two years ago and released from captivity about a week ago.
This information is from Swiss media citing a rebel group operating in southwestern Libya that is on bad terms with Haftar.
The group claims they intercepted a transfer of 50 suicide drones and large sums of money transferred by 5 men affiliated with the Islamic State.
The men allegedly came from a military base controlled by the Haftar forces and returned to Niger.
The so-called jihadists have already made additional trips to said base, though I'm not quite sure how the group has knowledge of this.
The Swiss authorities strongly deny that they paid any money for the release.
Although none of this has yet been confirmed, it would not be surprising as Haftar has made similar moves in the past with Emirati, US, Russian and other nationalities.
Haftar has contacts with the Islamic State and wants to establish himself as the ruler of all of Libya before he kicks the bucket.
So he does these "favors" to other countries where he pays the Islamic State to release their citizens in exchange for increased relations with said country. In return, he probably expects his ambitions to unite Libya under himself to be looked upon more favorably.