A lawyer of imprisoned Al Jazeera journalist Mahmoud Hussein has called for his immediate release days after Hussein completed the maximum period of detention permitted in a pre-trial arrest in Egypt.

In a letter of grievance submitted to the head of Egypt’s state security earlier this week, Hussein’s lawyer requested his client’s release, even if it were to come with bail terms.

The move comes as a top court in Cairo renewed Hussein’s detention for another 45 days earlier this month.

His defence team have yet to receive a response from Egyptian authorities.

Hussein has been held for more than 18 months as of June 21, which is the maximum period of detention permitted for an individual being investigated for a felony, according to article 143 of the Egyptian penal code.

According to the Criminal Procedures Law, authorities should have either released Hussein or referred him to court by the 18-month mark.

The Egyptian journalist was arrested on December 20, 2016, upon his arrival in Cairo while on annual vacation visiting his family.

Five days after his initial arrest, Egypt’s interior ministry accused Hussein, who was based in Qatar, of “disseminating false news and receiving monetary funds from foreign authorities in order to defame the state’s reputation”.

Since then, he has been put in solitary confinement, denied his legal rights, and has yet to be formally charged.

Hussein suffered a broken arm and has been refused proper medical treatment for his injury.

Al Jazeera has condemned the repeated renewals of his detention, denies all allegations against Hussein, and demands his immediate and unconditional release.

In February, the United Nations called Hussein’s case one of “arbitrary detention”, saying the “appropriate remedy would be to release Mr Hussein immediately”.