The income tax department is surveying the British Broadcasting Corporation's (BBC) offices in New Delhi and Mumbai.

Here are the top 10 things you need to know.

The income tax 'surveys' are not the same as income tax 'raids'.

The surveys are being conducted at BBC's offices in KG Marg, Delhi and Kalina in Mumbai.

Employees present in offices were first told to not use the systems & their personal phones, following which they were told to leave. The phones of officials & landlines have been put on restricted use by officers.

The tax department is alleging non-compliance with the transfer pricing rules & diversion of profits, sources told CNBC-TV18.

The department is seeking details on the alleged manipulation of prices for unauthorised benefits, including tax advantages, sources said.

The BBC issued a statement saying it is fully cooperating with the income tax authorities at its offices in New Delhi & Mumbai.

The surveys led to the opposition & the BJP taking digs at each other. While the Congress called the surveys an 'undeclared emergency', the BJP called the BBC 'corrupt'.

Last month, the Centre cracked down on the BBC documentary Índia: The Modi Question', & ordered social media platforms such as Youtube & Twitter to delete videos & tweets that comprised footage from the film. The documentary has triggered controversy in India as well as abroad.

Earlier in the day, Union Minister Amit Shah had told news agency ANI that the truth always emerges despite all the conspiracies around it, regarding the BBC documentary on Prime Minister Narendra Modi.

The BBC is United Kingdom's publicly-funded broadcasting system and it operates under a royal charter.