Emma Watson
Emma is being quizzed by immigration officials. Reuters

Hollywood star Emma Watson is facing a probe from immigration officials over claims that her American housekeeper worked in the UK illegally.

According to reports, the maid may have worked at the British actress's London home without a valid work visa. It is thought she only held a tourist visa, which bars foreign visitors from working in the UK.

The unidentified woman, who began working for 24-year-old Watson at her New York apartment in early 2013, was reportedly stopped by UK immigration staff, who questioned her about how she would pay for her stay in the country.

She was allegedly brought to the UK on a tourist visa in September 2013 and worked for the Bling Ring star until February 2014.

Border agency officials are thought to have started their investigations after receiving complaints that the employee was being paid to assist Watson at her £2m Islington home.

A source at the Home Office said: "An allegation has been received and processed and has been allocated for further action."

Watson, who catapulted to fame playing Hermione in the Harry Potter franchise, could face a £10,000 fine if authorities find the housekeeper was employed without the correct work permits.

The brunette beauty is yet to comment on the claims.