Lawyers for a flamboyant former Formula 1 kingpin wanted over allegations of money laundering in his native India say they have grave concerns about his treatment in custody should he be extradited to face trial.

Entrepreneur Vijay Mallya, chairman of the UB Group and former co-owner of the Silverstone-based Sahara Force India F1 team, is accused of securing vast bank loans for an airline he knew to be in financial turmoil before laundering the cash to fund his racing team, a court has heard.

The aviation magnate denies choosing to inflict losses on the banks rather than surrender his lavish lifestyle when he applied for a series of corporate loans. His lawyers say pressure from India to extradite him is “politically motivated”.

Speaking at the conclusion of a lengthy but truncated extradition process lasting around 18 months, Mr Mallya’s counsel Clare Montgomery said there were fears about prison conditions in India where her client would await trial.

She told Westminster Magistrates’ Court: “India has made assurances that Mr Mallya will be treated ‘adequately’. That was their favourite phrase – ‘adequately’.

“It turns out that when you ask questions about lighting and ventilation they provide you with a video that is, we submit, falsified.

“They say the lighting is sufficient to read by. Then they make a video that clearly shows the gloom that settles on the building.”

She said the video gave the impression the prison was in better condition than it was.

“Somebody’s done a very hasty clean-up job before the video was shot. Somebody has certainly been tidying up so as to provide you with a varnished version of prison conditions.”

Ms Montgomery cited the evidence of John Armstrong – a member of the so-called Chennai 6 Britons who were held in India for four years over weapons allegations, before being cleared on appeal – as a reason to have serious doubts about the Indian authorities.

She told the extradition hearing: “Embassy interest (in his case) was ultimately worthless in getting rights for him.

“We suggest a prison visit to allow you to have an expert opinion, unblanched.”

Mr Mallya, 62, was arrested in April last year by the Metropolitan Police’s extradition unit on behalf of authorities in India.

He entered the UK on a valid passport in March 2016.

The court previously heard India’s Enforcement Directorate has been gathering evidence as part of its investigation into the tycoon’s debts, totalling £977 million, linked to Mr Mallya’s Kingfisher Airlines.

Summing up in the case is due to conclude on Wednesday.

Chief Magistrate Emma Arbuthnot will then decide whether there is a case for the defendant to answer in the Indian courts.

The decision is due to be handed down at a later date.