Two of the women are sisters of Pakistani origin and were assaulted in front of their father. They were all members of a pro-Palestinian aid convoy bound for Gaza who were travelling through Libya.
There are conflicting accounts of what happened when they were seized at an army checkpoint outside Benghazi, the main city in eastern Libya, in the early hours of Tuesday.
The country’s deputy prime minister Awad al-Barassi visited the women in hospital after the attack, and said they were raped and their two male companions were beaten up.
However, Abdul Barghathi, spokesman for preventative security at the defence ministry, said he had no report of rape.
He said: “There was no rape, just touching. Because there is no British consulate here, they were handed to the Turkish consulate.”
Huseyin Oruc of IHH, a Turkish humanitarian relief organisation which negotiated the release of the kidnapped group, said the women were attacked and robbed. He said their alleged abductors included a taxi driver and a group of men in military uniforms.
A Foreign Office spokesman said: “We are aware of an incident in Libya involving a number of British nationals who were part of an aid convoy. We are providing consular assistance.”
The five had been travelling with a convoy taking ten ambulances to Gaza. With sea routes to Gaza cut, they had opted to drive the ambulances through Europe to Morocco, and then along the North African coastline to Gaza.
The convoy was stopped at the Libyan border with Egypt by Egyptian officials last week, and after waiting a week the five decided to fly home, driving 200 miles to Benghazi and arriving in the early hours.
A group of armed men at an army road block captured the five, subjecting the women to an hours-long ordeal before being found. Police say one of the women was found with her captor 40 miles from Benghazi, where she was freed and her attacker arrested.
Officials said four men had been arrested in connection with the incident.
An army official said those arrested were believed to be former members of the security forces who were dismissed from their jobs a few months ago.
Neither convoy organisers nor officials have yet given full details of the attack, but Benghazi is rapidly acquiring a reputation for lawlessness.
Last September, US ambassador Chris Stevens and three of his staff were killed in an attack by Islamic militants on the American consulate in the city.
More attacks on the British, Italian and Tunisian consulates have convinced most foreigners to leave the city, which is home to militias sharing power with government police and military units. The attack is a reminder of the limited control Libya’s government has in much of the country.
It is the latest in a series of violent assaults on aid agencies and diplomatic missions in the region where authorities have been battling to provide security since Muammar Gaddafi was overthrown in 2011.
In June, two British bodyguards were injured in an attack on a convoy carrying the British ambassador to Libya.
UK nationals have been urged to avoid the region for some time because of the high threat of criminal and terrorist kidnappings.
The Foreign Office has advised against all travel to much of Libya, and all but essential travel to Tripoli and a handful of other towns.
In January, the Foreign Office urged Britons to leave Benghazi after it became aware of a “specific and imminent threat”.
The French military action in Mali, which has received British support, has also raised the threat of retaliatory strikes on westerners.