Tony Blair's sister-in-law has converted to Islam after having what she describes as a "holy experience" during a visit to Iran.

Journalist and broadcaster Lauren Booth, 43 – Cherie Blair's sister – now wears a hijab whenever she leaves her home, prays five times a day and visits her local mosque whenever she can.

She decided to become a Muslim six weeks ago after visiting the shrine of Fatima al-Masumeh in the city of Qom.

"It was a Tuesday evening and I sat down and felt this shot of spiritual morphine, just absolute bliss and joy," she said in an interview today.

When she returned to Britain, she decided to convert immediately.

Booth – who works for Press TV, the English-language Iranian news channel – has stopped eating pork and reads the Qur'an every day. She is currently on page 60.

Booth has stopped drinking alcohol and says she has not wanted to drink since converting.

Before her spiritual awakening in Iran, she had been "sympathetic" to Islam and has spent considerable time working in Palestine, she said, adding that she hoped her conversion would help Blair change his presumptions about Islam.