The estranged husband of murdered Australian teacher Gabrielle Maina, and his cousin, have been released in Kenya without charge a week after their arrests.

Ms Maina’s estranged husband, Cyrus Bernard Maina Njuguna, and his cousin John Njuguna Waithira, were arrested in connection to Ms Maina’s murder last Tuesday.

A Kenyan magistrate ordered their release after no charges were laid.

Ms Maina, a 40-year-old school teacher, was shot dead by armed men who were riding a motorbike as she was walking near her home in the Nairobi suburb of Karen on October 19.

Police were granted a seven-day extension for the detention of the two men after their arrest to allow more time to gather evidence.

Both men maintain their innocence.

Ms Maina and her husband were separated at the time of her death and have two young sons.

Ms Maina was awarded a restraining order against her husband in April this year.

Her husband’s lawyer, Wilfred Nderitu, said his client was not in the area at the time of Ms Maina’s death.

“There is evidence that is capable of corroboration by many people, as many as 10, that Cyrus was in his office at the time that the murder took place,” Mr Nderitu said outside court last week.

“Therefore, there is no way he can be placed at the scene.”

Ms Maina was the head teacher at Hillcrest Preparatory School in Karen.

She had previously worked as a teacher in New South Wales.

Ms Maina’s family said funeral arrangements were on hold and no family member had travelled to Kenya for the court proceedings.