A "whistleblower working for the UN", I don't know what to make of this story but post these updates. Personally, I doubt this. Sounds like propaganda.
Libya: GNA militia used bombed migrant detention center for weapons, sex traffic
The migrant center recently hit by an airstrike in Tripoli, Libya, was being used to facilitate sex traffic and store heavy weapons by the Government of National Accord (GNA), according to a whistleblower working for the UN in Libya.
The Tajoura migrant detention center, where a Libyan National Army (LNA) airstrike killed at least 53 people and triggered an international outcry on Wednesday, and the nearby Al Sabaa detention center, were both being used by GNA forces loyal to Prime Minister Fayez al-Sarraj to store anti-aircraft ammunition, missile systems and other weapons, alleged a Libyan UN worker.
Speaking on condition of anonymity due to the dangers of his work, the UN whistleblower told Al Arabiya English: “We go in and out of the detention centers to administer humanitarian aid. The team has seen the weapons stored in the Tajoura and Al Sabaa detention centers since the start of the war in April.â€
Read more at: https://english.alarabiya.net/en/News/north-africa/2019/07/07/Libya-GNA-militia-used-bombed-migrant-detention-center-for-weapons-sex-traffic.html
