"We filmed for three or four hours,'' she said, speaking from the base on her mobile phone.
"I was filming the last shot and some security guy said what are you doing? They said we were supposed to get proper permission.''
Ward was held for five hours, including at least three hours at the base, before being transferred to an intelligence facility at Ain Zara in southern Tripoli. She told the Guardian she was in good health and had not been mistreated.
Her equipment had been confiscated by Libyan officials and she was told to report back tomorrow (Saturday).
The Foreign Office in London said they were investigating.
Since the fall of Libyan leader Muammar Gaddafi, the naval academy has become an IDP camp, housing around 2,500 Tawerghans - descendants of black African slaves - whose town, home to 30,000 people, was razed by rebels who accused the town's inhabitants of loyalty to Gaddafi during a crazed haze of retributive violence.
Gaddafi used Tawergha as a base to launch a sustained assault on neighbouring Misrata during last year's insurgency.
Abductions of Tawerghans from checkpoints and hospitals have become increasingly common, as are arbitrary arrests and extra-judicial killings.
In February, a militia from Misrata stormed the naval academy where Ward - who has official accreditation - was arrested.
By the assault's end a 63-year-old woman had been shot point-blank in the head, and two boys, neither 15-years-old, were laying face down on a nearby beach, one was shot in the back 10 times.
Libya has been plagued by a spate of retributive violence since the fall of Gaddafi.
Alleged Gaddafi loyalists continue to be stalked across the country, while an estimated 8000 people remain in detention, uncharged.
Two British journalists working for the Iranian channel Press TV were detained by a militia for around three weeks earlier this year, accused of spying, while the country's interim authority began passing laws stifling free speech.
The National Transitional Council, passed Law 37 (2012) - reminiscent of draconian Gaddafi-era laws according to rights groups _ which criminalised the glorification of the former regime, including Gaddafi, and anyone who insults "the prestige of the state'', its institutions or the Libyan people, as well as those who publish news which "harms the Feb 17 Revolution''.
The law was later ruled unconstitutional.