Tulip Siddiq, the anti-corruption minister, faces increasing demands for an investigation into her property interests as it emerged that her brother and sister are associated with a political think tank accused of spreading false propaganda.

Siddiq has close links with the Awami League party in Bangladesh, which is led by her aunt Sheikh Hasina, who was deposed as prime minister in August amid allegations of corruption.

The Labour MP owns a £700,000 flat in King’s Cross, central London, which was given to her by a political ally of her aunt.

She has also lived at a £650,000 flat three miles away which was given to her sister, Azmina, 34, by one of their aunt’s advisers.