An investigation has been launched after a mobile phone found hidden in the House of Commons was reportedly believed to have been planted there to play sex noises during prime minister’s questions.

The device was found during a routine sweep of the chamber on Wednesday.

The Metropolitan police said they believed it was placed there on purpose to disrupt proceedings in the house.

The phone had been hidden near the frontbench to broadcast adult content in the middle of Keir Starmer’s weekly noon showdown with Kemi Badenoch, the Times reported.

The Met said: “On Wednesday 3 September, a mobile phone was found during a routine search of the House of Commons chamber by Met officers. Inquiries have led officers to believe that the phone was purposely placed in a location with the aim of causing disruption to business in the house.

“An investigation has been launched and inquiries are ongoing. We have updated the speaker and clerk of the house.”

A parliament spokesperson said: “Parliament is a public building and we facilitate the visits of thousands of people to the estate each week.

“The safety and security of everyone who works or visits here remains our top priority, and we have robust and proactive security measures in place. This includes ensuring that visitors and their belongings are security screened, along with monitoring and routine searches of areas that are open to the public.

“While we cannot comment on the detail of our processes, we can confirm that a mobile phone was removed from the Commons chamber on 3 September, demonstrating the effectiveness of the security measures we have in operation.”