They spent their first night of 'freedom’ under the supervision of Iran’s Foreign Ministry and are due to be handed over to British diplomats this morning.
Doesn't sound much like "Freedom" to me. They could as easily been handed over to the British Embassy (or interest section if the UK doesn't have an Embassy in Iran), or for that matter to a 3rd country embassy, like the Swiss or the Swedes, or even Kuwait or the UAE.