A Saudi Arabian app that can be used to track women and prevent them from travelling will be investigated by Apple, its chief executive has said.

In an interview with NPR, Tim Cook said he wasn't aware of the Absher app but would look into it.

The app, which offers access to government services, has been criticised by human rights groups.

Democratic senator Ron Wyden has called for Apple and Google to remove it from their stores.

Women in Saudi Arabia need to get permission to leave the country from a male guardian, usually a father or husband.

The Absher app, which is designed for a range of government services, such as renewing driving licences, makes the process of allowing or prohibiting travel a lot easier, and it can be done via a smartphone.

Originally designed for the Ministry of Interior, the app has been in use for several years and downloaded more than a million times.

An investigation from website Insider exposed how it was being used by male guardians to register wives, sisters and daughters to either restrict or permit international travel.

The man receives a notification if a dependent woman attempts to leave the country.

Human Rights Watch told the publication: "Apps like this one can facilitate human rights abuses, including discrimination against women."

In an open letter to both companies, in response to the report, Mr Wyden wrote: "It is hardly news that the Saudi monarchy seeks to restrict and repress Saudi women but American companies should not enable or facilitate the Saudi government's patriarchy."

The app has also been used by some women to secretly change the settings on their male guardian's phone so that it allows them to travel, the Insider reports.

Google has not responded to requests from the BBC for comment.