British foreign secretary Philip Hammond on Monday welcomed the release of Australian journalist Peter Greste from an Egyptian jail, but called on Egyptian authorities to release the other journalists and political detainees still behind bars in the country.

The Al-Jazeera English journalist had been imprisoned for over 400 days on charges of spreading false news and aiding the Muslim Brotherhood, a group now outlawed by Egyptian authorities.

Greste's release and subsequent deportation was made possible due to a law passed in late 2014 that allows for foreign convicts to be transferred to their country of origin to either be retried or to finish serving their sentence.

"I welcome the decision by the Egyptian authorities today to release Peter Greste," Hammond said in a statement issued by the British foreign office on Monday. "However, I remain concerned that Mohamed Fahmy and Baher Mohamed remain in jail."

Egyptian-Canadian journalist Fahmy and Egyptian journalist Mohamed were co-defendants in the Al Jazeera English case, and are now serving sentences of seven and 10 years respectively.

Hammond also urged the Egyptian government to review the sentences against British nationals convicted in absentia in the case.

"It also appears that charges remain against the other journalists convicted in absentia, including British nationals Dominic Kane and Sue Turton,” he stated. “I call on the Egyptian authorities to review their sentences as a matter of urgency."

"We continue to believe that stability and prosperity in Egypt is dependent on open and inclusive politics and on full respect for the rights contained in the Egyptian constitution," Hammond added. "I call on the Egyptian government to take further action to ensure the release of other journalists from prison, to release political detainees and to relax restrictions on civil society."

Egypt consistently denies political detainment, and assures that anyone imprisoned in Egypt is awarded due process.