The Conservative Party is investigating claims a Tory MP watched porn on his mobile phone while sitting next to a female minister in the Commons chamber.

The incident was raised by a minister at a regular meeting of Tory MPs on Tuesday night, the BBC understands.

Another MP corroborated her account.

The name of the MP accused of watching porn was given to chief whip Chris Heaton-Harris, who is in charge of party discipline. His spokeswoman said he was "looking into the matter".

"This behaviour is wholly unacceptable and action will be taken," Mr Heaton-Harris's spokeswoman added.

The MP under investigation has not been publicly named and it is not known at this stage if they are a member of the government.

At Prime Minister's Questions, Green Party MP Caroline Lucas said 56 MPs were under investigation by the Parliamentary authorities for sexual misconduct, including three cabinet ministers. She asked Prime Minister Boris Johnson if sexual misconduct was grounds for dismissal under the ministerial code.

Mr Johnson replied that "sexual harassment is intolerable" and was "grounds for dismissal".

At Tuesday night's meeting, which was first reported by The Sun and The Mirror, women Tory MPs shared accounts of alleged sexism and harassment.

Asked about the allegations about an MP watching porn, Conservative MP Brendan Clarke-Smith told the BBC's Politics Live such behaviour would be "unacceptable in any workplace".

Labour said it would be a "sackable offence" for MPs to watch pornography in the Commons chamber.